Start there. Get a mostly flat setting going (from reading the manual - Bass/Mid/Treble knob at 12 noon - the frequency knob can be anywhere to start). On your bass, turn the tone knob all the way bright, turn the volume 100% up and start playing. Turn a knob and start playing. One knob at a time. That is the only way you will learn how the unit works. Try little boosts and cuts to start with. It's a lot easier than you think. Follow your ears!
Helpful EQ points - 4khz - average area where speaker cones roll off high end and anything higher goes into the tweeter.
1 to 2khz - Pick/finger clarity zone
30-50hz - Lowest notes the majority of bass rigs can put out. DO NOT boost heavily here unless the cabinet can handle it (many cannot at loud volumes).