Sal, there's no reason you can't be playing some blues in 6 months. If you learn the basic open chords first and learn the simple 12 bar blues format using the I, IV, and V chord progression, then you can play along with virtually any blues song pretty quickly. There are lots of good lessons on here to show you the way. Add a few 7th chords to your portfolio, particularly A7, B7, D7 and E7 and a few minor chords (Am, Em) you get a bluesier sound and some variety in your strumming.

Learning to play lead is an altogether different level of complexity that is really beyond a six month learning curve unless you are going to dedicate a serious amount of time to it. Check out the lessons on the pentatonic scales to get you started.

Bruce