Arrive early for your pick of the gen admission seats. If you have access issues call the venue in advance so they can have a chair for you in the lobby, and avoid standing for a prolonged period of time prior to the doors opening.
I found a great site where you can reserve your parking online. Parking Panda. If the garage is FULL you still have a spot. We went to the show on a Saturday night so it was definitely worth it to reserve our parking.