How to record a mix
1.) Buy a cheap audio interface
2.) Plug mixer into interface (you might need to buy RCA->1/4" or RCA->XLR couplers)
3.) Download Audacity:
http://audacity.sf.net/
4.) Hit record
5.) Mix
6.) Profit
As far as getting gigs, you really have to go out to parties a lot. Just saying "YEAH MAN ILL DO REAL GOOD I PROMISE" isn't good enough, in ANY music genre. I've been booking and managing myself/my bands for a long time, and this is true anywhere.