LISTEN TO ME RIGHT NOW
i learned this from a very famous jazz/classical guitarist. when learning a chord progression, never try to learn it at full speed right off the bat. do it as slow as you need to, without strumming, being absolutly positive your fingers are in the right place everytime. gradually start strumming and increase speed. this will build a muscle memory, whereas tryng to play it full speed and not getting your fingers in the right place everytime will not. also, learn pendulum strumming as soon as you can because it is vital for many popular songs
I don't know about this, maybe its just me, but when I look at songs in The Real Book and I learn em, I find I master changes better when I do do it at full speed, kinda spin on an old orchestra teacher I had who would have us sight read music at full tempo and would never slow it down.
But you do what works for you.
and also, I didn't learn scales until about...4 months after I started playing guitar, I learned a couple of simple songs first, but I hated my first guitar teacher, stupid punk kid all he did was give me some green day songs (even though I like green day). Easy songs still remain nirvana (most things), smoke on the water, Seven Nation Army (I actually was messing around with this the other day and just improvised on it and its a good song for improv and extended solos).
Good first scale, Aminor Penetonic, cause you can solo with it, and the blues scale only has one more note.
and yes, PLAY WITH OTHER PEOPLE.