Welcome to Dwarf Fortress, randyshipp!
Have you picked up the utility
Dwarf Therapist? It is incredibly useful for keeping track of which dwarves have which labors enabled, and adjusting as necessary. Once you have a fort active in the game, just open Dwarf Therapist alongside.
My best guess is that either you don't have a dwarf with Fish Cleaning or Fish Dissection enabled, or that the one with those skills is your Expedition Leader, who as you mentioned, is currently indisposed. If you don't want to use Dwarf Therapist, you should be able to enable the labors by viewing a dwarf (v key, then move the cursor near a dwarf), then pressing p -> l to bring up their labor menu and enabling it under the Fishing/Related menu. (I apologize if my explanations are oversimplified - I don't quite remember how much the tutorials would have given you at that point.)
About helping your Expedition Leader - Dwarves who are in strange moods will, as you know, eventually go insane if they can't get the materials they require. They won't go insane, however, if they're in the process of gathering materials. There's a bug, whereby a dwarf who is assigned to a burrow that includes the main material they need for their artifact but doesn't include the workshop they've claimed will endlessly run back and forth from the workshop to the stockpile, claiming all the resources from the burrow one at a time. If you want to keep your expedition leader alive, and have enough stone, you can make use of this to give yourself time to get some wool and silk cloth.
Burrows are a bit of a challenge at first glance, so I'll give a quick explanation. Pressing the w key brings up the burrow menu. Initially, you won't have any, but the option to press a to create one should appear on the right. Once created, the burrow won't have any designated tiles, and will just show up as "Burrow 1". Pressing enter will allow you to designate the burrow in the same way you designate tiles for excavation. In this case, select a space that is some distance away from the workshop, and is over an empty floor - I'd recommend a 3 by 3 area. You can also press n to name the burrow at this time if you so choose, and it's not really necessary. Once the area is designated, press escape to go back a step, then press c to bring up a list of citizens you can assign to the burrow. Highlighting your expedition leader and pressing enter will cause his name to change from white to green. With your expedition leader now assigned, you can press escape twice to leave the burrow menu.
The next step is to define a stone stockpile where you designated the burrow. Press the p key, then the s key to set it to stone, and designate as normal, on the same 3 by 3 area as before. After this is done, you may want to press the q key, highlight the stockpile, then press the s key to bring up the settings so that you can make sure that the only stone that will be brought there isn't bituminous coal, lignite, or metal ores - things that can be in short supply, and are more valuable when used for making coke or smelting/forging metal.
Finally, this last step may or may not be necessary - forcing your expedition leader to start gathering items again. Press the t key, then highlight the workshop he's claimed. You should see a list of items - probably only two - that are contained within. One has a B in square brackets next to it, and is the item the workshop is made out of. The other is likely to have a blue TSK next to it, indicating it's been claimed for use in the job the workshop is currently being used for. Highlighting this second item, then pressing f to forbid it and escape to return to gameplay, should cause your expedition leader to run off in search of a new stone. If you've done the above, and there's stone ready in the burrow, he should run there, claim one, take it to the workshop, and then - because the stone is no longer in his "assigned work area", go back to get another that he's "allowed" to work with. The stones already in the workshop will remain marked for the task.
By making the dwarf run back and forth from the stockpile to the workshop, you delay his insanity. He's gathering items, so he won't go crazy, giving you as much time as you need (provided you keep feeding him stone) to get some cloth for him to finish the job with. When you have the cloth available, remove the dwarf from the burrow, and he should go claim the last of what he needs, then begin work once he gets back to the workshop with it.
There is a side effect to be aware of here. Every additional item your dwarf grabs will expand the description of the final product and provide a bonus to its final value. This is how the infamous artifact Planepacked was created, and may result in your artifact referring to itself. This is part of why I suggested making sure the burrow was some distance away from the workshop - the more time your dwarf spends traveling, the fewer stones he will have claimed by the time he begins work, and thus the lower the likelihood of your artifact having an astronomical value that attracts enemies before you're ready.
Hopefully I haven't taken too long in writing this, and haven't bungled the explanation. Good luck.