The first step is a good washing/cleaning.
I suggest using the Two Bucket Method.
Here is a link ->
https://amiracledetailing.com/files/Two_Bucket_Wash_Method.pdf
Shampoos, towels, wash mitts, etc. have come a long way since "the early 2000's".
I suggest 2 Grit Guards, a
Merino Wool Wash mittand
Reset Intensive Car Shampoo
Drying is another subject. I use a
Metro Air Force Master Blaster but a quality leaf blower will work
IF it is never used for leaves.
Any leaves, dirt, or debris can get it the intake and blow on the paint. If you must use one create a filter to put over the intake.
Drying Towels: I like the
Microfiber Madness Dry Me Crazy (25" x 17") or the
Microfiber Madness Chipmunk (25" x 17")
Below is a link to a short video that shows the "Two Bucket Method"
https://www.youtube.com/watch?v=QDBMvKKTV28
Does it need polishing? Do you have light scratches and swirl marks?
For the PC I recommend a 5" backing plate to enable better control.
I'd suggest the Meguiar's® 5" Soft Buff DA Backing Plate,
DBP5
If it doesn't need paint correction for light swirls the I suggest:
Rupes UNO Pure Universal Ultrafine Finishing Polish
I have had very good results creating a high gloss finish with this product.
For the finishing pads I like both the
Rupes DA White Ultra Fine Finishing Foam Pad 5" or the
CarPro Gloss Pad 5"
After polishing be sure and clean any polish of the paint surface with a diluted IPA or (my favorite)
Carpro Eraser
Now that the surface is polished and cleaned you are ready for the Last Step Product (LSP).
There are multiple coating products CQuartz Lite (easiest) and Cquartz UK 3.0 (50ml Kit) (better looks and longevity)
Coatings can be a little tricky to learn to apply and remove correctly but they have the best gloss and durability.