Playing bass is way way differant from playing guitar.

It would take a miricle for you to learn it in 2 day's. Just try as hard as you can on the basic's and don't get carried away and start trying to learn treble and twang.

You'll probebly just be standing there tickling G all night anyway.

Your bro can't expect you to do all that well by monday anyway just do your best and make sure they put up chicken wire in front of you. j/k