Being a dev is full of highs and lows, if you can't draw try using a 3D engine like Daz, or even Honey select.
Ren'py is really easy to use once you got the hang of it, the hard part though is using it correctly to have really interesting menus and interactions.
I do all by myself, coding, story, renders, I only have a proofreader, and the help of my community sometimes !
Good luck with your project friend, and if that's what you want to do, don't give up and do your best !