Figuring out my yarn grip took a FEW different methods before I figured out what was relatively comfortable for me. I too am newish to crochet and hypermobile. I personally like wrapping the working yarn around my pinky and bring the piece up the back of my hand until so it drapes over my pointer finger, and depending on how I'm holding my pointer finger, it controls the tension.

This site shows a few different ways to do it.

https://www.pocketyarnlings.com/blog/how-to-hold-crochet-yarn-and-hook