is it easy to screw the paint more if you have no idea about cutting and polishing?
thats what im wworried about lol
Yes.
It actually takes a bit of skill and knowledge/practice to do it properly. You can do it yourself but knowing some basic rules helps.
Most off the shelf stuff is pretty weak to be honest, just don't use an old school cutting compound as they aren't designed for clear coats and will scratch the crap out of it.
To do it yourself.
Start with a Good wash and remove any tar while you are at it.
A clay bar with heaps of lube is pretty much mandatory before polishing as if there is any dirt stuck to the paint if could come off during the polishing stage and scratch the paint.
Polish in a closed environment, or at least a still day, out of sunlight.
Never use rags or terry towels for this. Microfibre cloths all the way. And fold them to wipe of residue, don't scrunch them up.
And find a good pure polish as most off the shelf polishes will lightly polish but also hide the scratches until the car is washed again, then the scratches will show again.
I don't use anything from Supercheap/Autobarn etc as its pretty ordinary. However Meguires Scratch x is alright.
I would be suggesting going to a proper detailing supply shop and getting some Polish from them if you wanted to do it yourself. I like Menzerna, but 3M and the Meguires Pro stuff isn't too bad.
Lastly remember to wax the car to help protect it from bugs/tar/crap etc