Been there 4 times (until COTA Moto GP).
Lots of the parking and camping right by the track. You might be able to do a paced ride on the track- check for tickets. Probably find cheaper/better tickets from the private sellers than purchasing from the track.
Downtown had a bike weekend (check schedule). Indy Mile isn't run during Moto GP weekend this year due to State Fair.
Get a Tenderloin sandwich at Mug N Bun.