Defineatley learn the pentatonic scales. THAT IS A MUST! If you know somebody that wants to jam, ask him/ her to help. Ask him to stay in one key and have you just play the different pentatonic scales. Also play them over and over until you know them backwards and forwards. Then try just turning on the radio or playing a CD. There aren't that many people I know that play guitar, so thats what I do most of the time.

If u get a teacher, ask him/her to show you the pentatonic scales, modes, and anything else he thinks of. My teacher likes to jam w/ me once in a while to check up on how well im doin. This helps a lot.

Finally, you MUST learn how to read TAB. If you don't, it'll be really hard for you to learn new songs unless someone shows you.

Good Luck