Alignment fixes the car not traveling stright and always wanting to turn a certain direction. Great prodecure to do and it revitalizes your car's steering abilities since one wheel isn't all crooked. Tire rotation is to keep tread wear even, you want the most tread in the front to give you best traction in the rain & corners.
Oil change oughta be pritty cheep, like 20$, jiffy libe charges 40$ and checks all of the fluids and tops them off as nessicary for free.
Brake pads varry, for OEM, I'm betting 30-60$ each pad. For good pads, like axxis, expect to pay a little more.
Get alignment. If you have a vibration, get them balenced. If your tread is less in the front than the back, get a rotation. Check your air filter while you're at it.