I have a Poulan 365 60cc tore down to put crank bearings and crank seals in. It might be a little over your head installing bearings and cranks though.
Maybe just staying with a top end rebuild and carb stuff to learn on first.
Someday to go back to this with 20"
Here is a Poulan 415 I didnt have to go as deep with. You could start with something like this. Runs a 24" with ease in hardwoods.
415 video after rebuild Poulan Pro 415 after carb soaking - YouTube
Maybe just staying with a top end rebuild and carb stuff to learn on first.

Someday to go back to this with 20"

Here is a Poulan 415 I didnt have to go as deep with. You could start with something like this. Runs a 24" with ease in hardwoods.


415 video after rebuild Poulan Pro 415 after carb soaking - YouTube