[help] where to start for real?

Made this guy today with a stick and some perfect to work with fresh snow and now I want to try taking some time with some real supplies and actually sculpting a head!

I am open to many things on the cheap-ish side (I know shit costs tho!) and I already have some carving tools from a print making class I took, but I'm not sure if I should get clay (and what kind) or a like a foam block (although not being able to go back is scary as a beginner lol) but any advice would be great!

I study figure drawing and I'm really interested in the human head/anatomy, so that is primarily what I would do/am interested in if that influences things. I’d also want to do it to scale! (Which I know impacts prices/supplies but as an artist outside of this medium I’m used to it lol!)

Thanks sm!