Do it yourself, patching a hole in drywall is easy.
Small holes under 1/2" diameter, just fill with patching compound. When it craters a little from drying, smooth some more on. Allow to dry, sand lightly and paint to match the wall.
Bigger holes take more steps:
1) Make the hole a regular shape. That's right, you're going to make it bigger. Get a drywall saw and cut it square, or else use a hole saw in your drill and cut it to a perfect circle. I really like the hole saw option.
2) use the dimensions of the square you have cut - or use the same hole saw! (that's why I like it) - to cut a new piece of drywall (look for scraps at the big box store, or small pieces they sell for just this purpose) that will fit inside the hole.
3) Screw a couple of pieces of scrap wood inside the hole. Cut it a couple of inches longer than the hole itself, so it bridges the gap all the way from one side to the other, and gives you a bit of room so you can put a screw through the drywall outside, through the wood inside. You want those screws to be an inch or so away from the edge, or else the edge of the hole will crumble. Screw through until you feel the wood start to push away from the inside of the wall, then reverse the drill and push a bit until the screw threads have loosened the drywall they're going through - you're backing the screw without letting it back out. Then forward again, screw into the wood until the screw head pulls to just below the surface of the drywall. This means you can spackle over the head cleanly.
Wood scrap at the top and bottom of the hole, to support your patch piece.
4) Patch piece lays on the wood, screw it down.
5) chamfer the edges of the hole and patch.
6) If it's a big patch (more than 6" by 6") you may want to tape the edges. Drywall tape - look it up, lots of great tutorials on YouTube.
7) Mud and sand until you're satisfied with the contours, skim coat, sand and paint.
Your total time from start to finish should be about two days, but your actual time spent working on the project will be about an hour, spread out over several little engagements.
You can do a great job and you absolutely DO NOT NEED A PRO. This is easy work.
Good luck with it.