Heya-
First a little history-
I a senior now, i have played saxophone since 6th Grade. 1 year alto, the rest Baritone, and now Baritone and Soprano. I am in Jazz band as well as our all-state Symphonic band (have a new teacher so who knows this year :( )
I also and a TA in the 6th grade band/jazz band.
Also Take privy Piano lessons for 3 years now (not a prep or rich, just have a really good cheap [$15 and hour she comes to my house and brings own music] piano teacher]

So since i am starting to TA in the middle school jazz band, and they are just learning how to play jazz, i figured i might as well learn to play bass with the kids.
I was able to get a... squire by fender bass from my "little sister" and a amp that seems pretty good.
I also am going through a DVD that it came with (yes i know, never teach yourself and instrument, but this is just untill the next jazz class. i dont' want to make a COMPLETE fool of myself)

So my only thing is, does anyone have any pointers, tips, advice... any at all?

Oh and, i tend to strum (right hand) with my thumb and third/fourth finger, is that allowed? *i have tendonitious, so i kinda have to stick with what is comfortable* I know i don't want to use a pick.

So any advice would be amazing. Thanks!