I think it depends on what kind of tailgate experience you are looking for. If you are looking for more of a family setting, I would say the lots on the south side of the stadium are more family oriented. That is where they set up the fan zone, which usually includes free food, games, tents, vendors, etc., and always has loud family friendly music. So more families end up on that side. I like to have more of a party vibe at my tailgates so I set up in lot 4 (North side) where more of the students go. I always set up with a group of about 5 to 10 people and usually end up with closer to 30 or more (depending on the game) that end up hanging out with us.
As far as music, i usually let those at my tailgate dictate the music that I play. My go to is country, and that is usually what I begin the tailgate with. But sometimes I go with hip hop if that is what everyone that shows up wants that day.
For food, it depends on how much money you are wanting to spend. As @ApisBull said above, having a food theme based on the opponent is a cool idea, but would generally cost more. Burgers, hot dogs, chips, etc. are more of a tailgate staple, and are cheaper. In the past, I have bought chickfila nugget trays, pdq chicken strip platters, and Publix hot n' spicy chicken wings, and they all seemed to be a big hit but also costly. If you are looking to bring a grill and prepare food, that is probably not the direction you want to go.