Need advice

Working on my old El Camino and need to wet sand the door and then polish it out. Had some areas that I filled and did some tough up paint. What sand paper grit do you use and what are the steps to complete. Could use any help-advice, never done this before and don't want to screw it up.

i am going to assume that the door is final coated. it would be good to know how many mils the clearcoat is. or how many coats. i am going to assume 2 coats. you will need a stream of clean water, 1200 grit wet/dry sandpaper, 2000 grit wet/dry sandpaper..a bucket of water with a few drops of liquid soap in it....i use dawn dishsoap. the soapy water will help keep the paper from building up. cut the sandpaper in half then fold into thirds. soak half the paper in the bucket for 5 minutes or so, this will let the paper soften a bit and let the soap penetrate. run a low stream of water over the area you want to sand, dipping the paper in the bucket often. be careful not to sand through the clear, especially on edges, corners, and curves. do the same with the 2000 grit. if you have a slow buffer with a sponge pad, use some 3m polishing compound. i use the "perfectit2" by 3m. do small areas at a time. about 1ft areas. if it is a dark color you may need to use a "hand polish compound" also by 3m. i have used mcguires scratch x with good success also. do not use a buffer with these products. they are designed to remove very light scratches and swirl marks. stand back, admire your wonderful job, comb your hair in the shine and smile!!!!
if ya have any question, just ask!!!!! you can do this!!