Hi, Justin, and welcome to WriteWords
It is a difficult decision as to which group to join, but as a full member you have the advantage of being able to join more than one, and/or you can move around until you find one you are happy with.
Although the groups are split into genres, you don't have to limit yourself in that respect. Some of the groups have gone a bit quiet so you might find yourself waiting a long time for feedback, but I think there are signs of life in the Non-Fiction group, or you might consider one of the fiction groups.
If you want time to think, you can always upload something in the Archive in the meantime.
- NaomiM