Back at camp now. I think my clay cup thing exploded somehow. I knew I was bad at pottery but I didn't know I was set-cereal-on-fire bad. I got a couple of "bricks" that have almost decent shape but I'm kinda scared to put them in the 'kiln' now. Any idea what I'm doing wrong?
Amateur pottery.
Okay, more helpfully. You probably didn't knead the clay enough. Air pockets are the most likely reason for a piece to explode in the kiln.
I guess I have to tell you how to do this properly too. Your best bet? Take small lumps of clay (small enough to hold in your palm comfortably), knead them in your hands vigorously - basically just squish them around - and then roll them between your palms to form thin snakes. Take a clay snake by the head - I mean, by an end - and start wrapping it around itself in a spiral, forming a kind of disk - and, as you go, gently offset the spiral to one side so that the disk becomes a dish. Make sure that the clay adheres firmly to itself all the way around without gaps. When you run out of snake, pick up another one and stick it on. Gently rub the inner surface - that's the concave one - so that you smooth out the ridges that show where the snake centers were. This should make a decent vessel, and this construction method can be scaled up to pretty much any form with enough snakes.
I still don't have any sharp rocks
They don't have to be flint-tool-level sharp for this simple purposes, even just a jagged piece of shale you find on the ground or dig up should do it. But even if you really can't find anything like that, your hands will do fine; you can likely break off a chunk of bark even from a larger tree (I've done it).
I was planning on cooking them over the fire in my cup...but for explosion-related reasons I don't have the cup anymore. My backups are still kinda mushy and might just explode if I put them over the fire. Any idea what I can use to heat it over my fire?
Well, I did just tell you how to make a better dish, BUT, since you probably want to eat sooner than later, if you're careful and don't actually stick the branch IN the fire, collecting some on a branch should do it. The sap will start to drip, but twirl the stick like cotton candy to keep as much on as you can, and it's okay if you lose some. The trees will make more.
ETA: Oh yeah, I was going to say, you can also use a rock. Again, though, put it NEAR the fire, not IN the fire. Incidentally, some rocks can crack in fire, and you might try putting any new kinds of rock you find into the fire to see if you can crack them and potentially get sharper rock fragments. From a safe distance, of course.
Should I try to kill the birds with a stick or throw rocks or something?
...Sorry man, your best bet is to grab it and try to break its neck or bludgeon it. Don't be squeamish, you ate worms.
How do I identify the part I'm not supposed to eat?
It's the big tube that goes from its mouth to its... not-mouth. The intestines, in particular, look like a big pile of intestines, that is, gross flesh-rope, basically. It might be safest to take a moment to go over the easily-identified organs you definitely can eat, of which the most important is the liver, a sort of brownish lump that should be in the ribcage and is probably one of the larger organs (although different bird species vary). The heart is also edible and is basically just a muscle; it is found in the ribcage, more or less right in the middle, looks remarkably like a human heart, and may still be pumping in a fresh kill. Both of these are unpaired organs, although the liver likely has two conjoined lobes. The pancreas in most birds is a kind of long tube usually found in a sort of fold of the digestive tract, shortly after the gizzard (the pouch that may contain stone or grit); it's not really much of a delicacy but is edible if you want to go to the trouble. The liver is also attached to the digestive tract (by the bile ducts), but far less firmly; don't confuse it for the pouches formed by the digestive tract itself. There are lots of other organs in a bird, but the heart and liver are the most useful as food. You can eat the brains and eyeballs, while I'm at it, but you don't have to. I know they're kind of gross.
Now, gizzards and intestines are in fact edible, but they need to be cleaned, and you're in no position to do that. The crop, however, is the very first pouch of the digestive system after the mouth, and may be full of undigested food the bird previously ate. Depending on the diet of the species of bird you found, you might be able to eat this stuff. Unfortunately, since I had you hunt using bugs as bait, you're probably just going to catch an insectivore, so this is not useful to you NOW, but as you get capable of hunting birds with other methods, or use other baits (ie, fruit), you should remember this. Avoid unfamiliar berries, though, as plenty of fruits are poisonous to mammals but not birds. You'll be most lucky if you catch a seed-eating bird, from which you can potentially harvest a haul of edible seeds and nuts. Even with the birds you're catching, though, anything in the crop can be repurposed as bait. The crop doesn't harbor the kind of bacteria that can harm you, contain any acid, or, most importantly, contain any feces, so you can eat it once you've washed it out, if you're desperate for more nutrients. It's made of muscle, but isn't the kind that's especially palatable - still, food is food.
And uh...Ok, I just ate the berries whole without thinking about it. But before too long I think I'll have the seeds buried somewhere anyway.
That is one way to do it. I mean, that's how the birds do it. Farming is something that will take a long time to be useful, but you should get it started as soon as possible so that a long time is SLIGHTLY LESS long.
How can I make two heads without a cutting tool? I can just kinda rub a stick hard on a rock to get a kinda-point, but I'm lost on how to make it split.
You can just start with a forked branch. Still, don't shoot for spear-fishing right now, as you probably have no way to clean the fish, and fish are nasty to eat without butchery. Well, fish are nasty anyway. I think you should stick to mammals for now; you should be able to work your way up to squirrels using the same 'sticky trap' method, with the right baits (fruit, seeds if you find any).
Are your vines thick or thin? It sounded a little like virginia creeper, which are thin and only a little woody. If the leaves are very jagged and make a kind of star shape, and those berries are arranged in a shape kind of like a grape bunch but looser and less dangly, that or one of the related species would be my top guess. I'm not going to ruin the fun by posting pictures, though. If so, do not under any circumstances eat the berries, but you definitely should be able to braid the vines, especially younger ones, to make a kind of rope. Otherwise, you should be able to braid rope out of the blades and straws of long grass, although it will be a lot more effort. One thing you should check is whether the vines have little tendrils coming out of them that end in sticky pads that adhere strongly to the tree; this is a feature of virginia creeper. In any case, your next homework is to make some rope.