How to sound like...

I have a Epiphone Les Paule.

I would like to sound like Chuck Berry and Billie Joe Armstrong.

I cant really tune it in just with the guitarr. What more can I buy to get that sound? A new guitarr is tempting, but not in the budget. ;)

Check out this tutorial.. there are two more tutorials if you use the Sites search box..
http://www.guitartricks.com/tutorial.php?input=1638

Chuck Berry used semi hollow body guitars and almost all the stuff he played was written in keys not common for guitar, but more common for piano... Start by learning his songs...

For Billie Joe Armstrong.... once you have learned how to play guitar for about 6 months and learn basic barre chords - You'll sound exactly like him technically... gear wise. Basic Marshall and distortion. Mess around with cheap effect pedals.