Okay, let's see. If you haven't been playing long and are still getting used to bass in general, I would just start with the basics. When I started, I just stuck to the note that was written down. Like on the music sheets where the chords the guitarists are playing are written above the words, just stick with those for now. It will sound fine I promise, we can add flair later

. In your free time, learn scales. Learn your basic major scale patterns and learn your basic minor scale pattern.
For now, just learn the first one on here. It's called the Ionian major scale and it is your basic major scale. It's a pattern that you can apply to any fret/note.
http://www.angelfire.com/id/bass/major.html
Also learn your basic minor scale. Uh, I can't find the one I usually use. I'll make it up lol
G|---------------------------5-7-|
D|---------------------5-7-------|
A|----------------5-7------------|
E|--------5-7-8-----------------|
I'm not sure that that's legit. But it's how I roll.
Hope this helps!