Garage bands during the 60's usually practiced together (as a unit) once a week, maybe twice on occasion. But in learning to play guitar, you need to do some practicing on your own - at least once a day or more if you can tolerate it. This helps to build the dexterity in your fingers as well as improving your strumming and picking abilities. It'll hurt for a while, but as your fingers build calluses it will get less and less painful. ;o)
I started learning to play when I was nine after being shown a few basic chords and lead patterns (mostly from The Ventures) by my cousin and a couple of his Navy buddies. They had a band called The Nomads that played onboard ship (USS Coral Sea) as well as in different ports on occasion in the early 60's. But when they came to The City prior to shipping out to Vietnam, my parents let them practice in our garage, which peaked the interest of both my brother and myself. Long story short, they left their instruments behind with permission given for us to use them. Funny thing is when they returned from that tour of duty (about a year) and heard us playing guitar together, the lead player said, "Sure! I show you guys a couple of things, and now we come back only to find you're way better than us"...hahaha
This is a little bittersweet subject for me as I'm no longer able to play because of neuropathy in both hands, which has destroyed my ability. So now that YOU are a "rising rock-star", I have hope that you can take up where I left off...hahaha
Break a leg!