In the Amp Stickies section of the TB Amp forum (up top) you will find all kinds of archived discussions that cover a wide range of common topics for bass player new and old.
Here is one that may be helpful for you.
What Do Various Frequencies Sound Like:
EQ bassics thread | TalkBass.com
its a good place to start if you have no idea about Frequencies and EQ.
As you work this out, also try and remember that there is a fine balance between turning the knobs on your amp (they are there to turn after all) and overdoing your EQ settings. There is one school of thought that embraces "FLAT EQ" (even though its very difficult to really achieve). There is the "Smiley Face" EQ school of thought (boosted lows and highs, and scooped/cut mids). Personally, I generally try to avoid boosting EQ freq's too much at all, and use the EQ to address tone or room problems through cutting problem freq's. Another lesson I will pass on is that the sound you get by yourself, is NOT always (or even often) the sound that will work best in a band situation.
So, read the sticky I posted above, it will give you a reasonable idea of what the various freq's basically do and some idea of what they do to bass tone. Then go out and experiment until you get a tone that you like AND will work in any band situation you may be in.
it's not hard.
good luck