My 07' Accent with about 37,000 miles had two codes pop up:
P0301
P0300

The people at O'reilys cleared them so the check engine light isn't on anymore.
The first spark plug was checked and it looks fine and the others were fine as well. The gaps were good. They were at 0.39. I don't know what else it could be since I don't know much about cars so what should I do next?
Any one had any previous experience with this?

 

Yes
Broken intake valve spring. Take off the valve cover and inspect the valve springs VERY carefully with a light and magnifier.
(it's hard to see a broken spring, so you need to check carefully)
I was able to remove and replace the spring with a small spring compressor. That fixed it.

ALL the usual stuff:
spark plugs, wires, injectors...was all a big waste of time and money. The intake valve was stuck open....that's all it was.