Honestly, I can recommend you to look at the artists you like and incorporate parts of their style into your own. c: Like the lineart-thickness you talked about. I recommend Proko, Marc Brunet and Winged Canvas on YT, if you want to learn about art basics, staying healthy and finding your style.

I heard bad things about Proko, people saying that they are profit first and that they don't care about their customer base. But I will definitely give these other 2 a shot, tyvm for the reccomendation <3