My advice would be to either borrow some guns or go to a gun range that rents them, so that you can get a feel for what is most comfortable to you.
For example, my dad shot with a .35. I wasn't particularly comfortable nor capable shooting that particular weapon. My main has been a .243 for about 25 years. Though, I'm considering moving up to .270 for some of the larger game.
As others have said, a hunters safety course is a must, not only because it's a legal requirement, but I speak for others when I say that I don't want an irresponsible, uneducated person out there shooting around me. I sat in on my son's and I learned some interesting things about the laws in WA, as well (got my hunter's ed in Texas).
Hit the range as much as you can! Again, I don't want an untrained person shooting around me and my boy. Additionally, it's inhumane to shoot at an animal not knowing if you're going to give it a mortal wound or not. When I was a kid, I made that mistake one time and never made that mistake again. Believe me, when you have to slit a deer's throat because it can't walk, you grow up really quick.