If you are starting on oil changes and tire rotations, pick up a 1/2" gun.. Ingersol is typically a solid gun. Then get a 1/2" impact socket set. IIRC I picked mine up from Home Depot, the husky brand. They are technically lifetime, but you have to send them in. Sears would be another I would recommend if they are local. That way you can lifetime them nearly any day. You won't need both metric and standard as they are close enough at that size to make due w/o worries. I have just a metric set as most newer cars are metric only.
Whenever you buy sockets, get six point only. Aim for lifetime. this is one of the reasons much of my stuff is Craftsman. There's a SEars less than a mile away from me.
99% of the time I use deep 3/8" 6 point sockets when working on motors. There is occasion to pull out the 1/2" impact, but it's mostly 3/8". I tell guys to always hand me a deep well socket. It's rare that the shallow sockets are used, but they do get some use in the tight spaces.
Buy a hose clamp tool when you can. It's about the best $40 a guy can spend.
Then....buy a gearwrench 82248, you'll never regret that baby. It's the ultimate axle removal tool, along with many other things.
A multimeter
A basic test light
A soldering iron (home depot has a nice weller say 100/140watt for ~30)
Aim for those things and you'll cover a majority of the stuff you would need.
Nice to have
Pivot head ratcheting wrenches
E torx set
Torx set
Bolt extractor set
A basic two jaw puller
