No offense intended here, but if you have to ask... paint correction is extremely precise. It can take a fraction of a second or the wrong pad or any one of variety of things to damage the paint. Please spend the 2 or 3 hundred bucks and have an experienced shop clean and polish the paint for you. Then you can do your DIY ceramic coating. (For the record, I would let the pros do the coating too) You should be applying the coating immediately after the paint correction is done...as in within the same hour. Don't have it polished out and then wait a day or longer.
You spent a lot of your hard earned money to buy the car and you see the value in ceramic coating AND you know the importance of having it polished/paint corrected... leave this one for the pros. It can really bite you in the wallet if you goof it up.