For races, I am allowing fictional creations in the homo genus. So yea, you can have something that looks and acts like elves and dwarves. Merfolk, furries, and insect people are out though.
Technology, it's Pre-Colombian Americas. Think of the Americas in 1491. Stone and bone tools for the most part. Some limited Metallurgy, but very limited use as weapons (Individuals could have a copper axe, for example, but entire tribes wouldn't, unless you could provide an example of it being used large scale historically in that timeframe)
A lot of technologies are completly out because they didn't exist. Guns, for example, came over the ocean. I don't think America had any Gunpowder in that time, but if you can provide proof they did, I'll allow gunpowder.
For tribal size, don't put yourself in control off the bat from something that is a federation or empire. Also don't put yourself in charge of a city with more than 5000 souls. You can make what you are in charge of PART of a large tribe, but try to avoid making anything with more territory than 8000 square miles or more than 1 Tenochtitlan. There is room for multiple Inca/Rome/Mongol/Chinas, but there is an absolute limit on how much space there is in the world. So yea...
And yes, the examples are rediculous. I thought the names or the fact they got the space of a house gave that away, but I guess they didn't. If anyone creates a tribe that small, they will NOT be listed on the tribes group. Unless they control territory like mad. If 10 people control 20000 square miles, I'm not gonna say they aren't a tribe. I'd be too afraid of them.