Welcome to Austin! Austin resident here...
Sixth street lost a couple of staple bars, that said, if you come on a weekend avoid sixth street. Its like Bourbon Street yet somehow worse, probably all the college students.
However Casino el Camino has great burgers. Eastside Showroom for cocktails (go before last call and ask for the Final Word). AppSumo is right on sixth street, email them and say hi!
As for music:
Do512.com and austin360.com will have schedules of whatever strike your fancy. If you want more mellow, Most bars on South Congress, (here, despite geographic density "south" you refers to anything south of the river) are great.
Ill update this post more when im not on a smart phone.