To be honest, that's what they do, change the oil. They're also supposed to check/tighten all nuts and bolts. They will check to make sure things are to spec, no leaks, and then charge you a couple of bills.
I would buy a filter, change the oil, check your chain, cables, tighten screws, check lights and save your receipts. Save some money, or for peace of mind take it in.
Or use this as an opportunity to find a good local shop to work on your bike. Check around on local forums and see if there isn't a shop nearby that folks say good things about. They can do the things that are out of your comfort zone, and you can take care of the routine items, knowing you always have a resource if things go sideways.