I'm not knowlegable at repairs but I tried to perform my own tuneup.

So my car was giving cylinder misfire codes so I changed the spark plugs and one of the ignition coils. Still was having performance problems so I bought another coil to swap out. Now my screw is stripped.

Any advice on how to get a stripped screw out so I can continue to try and perform the tune up?

 

I'd start with trying an easy out tool. It's kind of like a drill bit but the blade is reversed. It bites into the stripped screw head as it reverses the screw. If it's the threads that are stripped you may have to drill it out and then see what the hole threads look like.

 

If you can get it in there use a dremel and grind a slot then a screwdriver to remove it.