Probably best to decide what type of work you want to do & go from there. Are you going to do metal fabrication, general maintainance work like oil changes, tuneups, tire rotations, exhaust work, or something like engine building, modifying vehicles by doing liftkits, etc?
General work like the tuneup & oil change you can get by with a set of decent handtools like combination wrenches, 3/8" ratchet & sockets a set of car ramps & a drain pan. Throw in a floor jack & set of jack stands and you can do tire rotation/changes, minor exhaust work, brake pads & such.
Fabrication work & you're looking at torches, welders, plasma cutters, tube benders & the like.
An air compressor & air tools will make most jobs easier & will make it possible to do jobs that you can't without one. Stay away from anything oiless in compressors & don't bother with cheap impact guns, both will be frustrating to use & in the case of the compressor will be so loud you will want/need hearing protection to be around it & if you have close neighbors they might have issues with it.