I'm not a 3D Modeller but I've tried before, doing some really simple things for a few of my games, I'll still give you my personal input if it helps:
1. "What did you do if you knew you wanted to model something, but didn't know how to make it or just make it look good?"
- I pull through if it's a simplet thing, otherwise I'll go find a free legal version on the web or ask a friend. If I can't find it, then I usually give up.
2- "Was learning how to 3D model things yourself hard/worth it?"
- Yes to both, but to me specifically what felt worth it was the fact that now I understood how UVs work. I am however traumatized by Blender's UI (jk), although I hope I don't have to do this again, at least too often?
3 - "This goes along with question 1, how did you gain inspiration, or know what you wanted to 3D model?"
- Planning the game comes before making the model, but what really inspired me to do it was that I really wanted to finish that game.
Having that said, I recommend you purchase models from a store or hire someone through commission, however if you're really into learning 3D modelling it should be worth it a lot more in the long run because that's a massively useful skill in indie game dev.