I will add this...
get there early with a input list and stage plot
soundguys love advanced info
Thanks...ever seen either of those things, im a total noob here...where can I get more info?
I'll sort of caution on this a little. If the sound tech is a real pro they'll likely appreciate the extra info, but, with a "5 bands/5 bucks" gig with a back line, they may not care about your stage plot : how you set up on stage, and may not care about your inputs, since they have it all laid out for one-size-fits-all from band to band.
Only mentioning as I ran into a situation where the venue asked for those stage plot/input specifics and then, after I turned them in, I was told - sorry, you have to set up this way and use what we have the way we have it. -- Fortunately the audio tech was not the same person rejecting the plot/input info, and was more amicable, but their hands were still somewhat tied as far has how we like to set up our personnel on stage - who goes where. So just be prepared to be flexible when giving such information, as well as possibly even humored or ignored. Day of show can be stressful for sound techs, so you have to roll with it.
If your bass is DI'd before your amp, then you'll have to trust the tech to balance you to his tastes out front, but, on stage, you can tweek your amp vol. a little to get a blend you like towards that equal presence with the guitar. At least that will help your performance and blend as you guys like to hear it. But, no harm in mentioning your forward blend with the bass.
As for recording, you can try that, too, but again, be flexible. Maybe ask well in advance of the show - days, if possible - to first see if the event is already being recorded. If so, then ask for a copy. If not, be as considerate as possible for what the tech can or can't do. He may not know how to run your recording gear.
For myself, as a person who's done live audio as well as recording, if I want to try to get a board mix to "tape" - if possible, I'll find out what brand/model the mixing board is and then research the manual on line to see what simple output options it has that would be the least invasive to take a line out from. Since I never want to impose, I like to know options and then ask permission, so dealing with it in advance, like AlembicPlayer said "get there early", is a good idea.
-- But having the tech hit "record" may or not go well in the midst of band change overs where the tech's attention is focused on moving the acts along. -- They may or not remember to hit "record" when it's time. -- It's a good idea to have a friend who knows - running the recorder in a very discreet way.
Lastly, if you are fortunate to get a line out from the mixer for recording, keep in mind, what the board balances with it's faders is also in consideration of what the amplifiers and live stage sound are kicking out into the room as well. This means that, for example, if the bass is loud in the room on stage to you, it may be quieter in it's level through the board, since stage volume is being factored into the overall balance to the listener.
In other words, a live board mix is not always representative of what it actually sounds like in the room. A sound board recording only reflects what is truly and exclusively controlled by the PA. So it's possible to get a board recording with really loud lead vocals and next to no bass (for example) - or, a board mix might sound unforgivingly perfect and dry, without the blend and ambience of the live room. You sorta never know. (Unless you're doing a more complex recording, like multi-track with separate mixing opportunities to balance levels just for the recording.)
In these situations it's a balance between the sound tech doing a good job for all the bands to serve everyone best, the audience especially -- as well as the bands being considerate of the event and being flexible. Everyone needs to accommodate one another. Being friendly and courteous goes a long way.