Sorry this got longer than expected. As a magnetite black owner, I'm in a constant struggle with my paint and hope I can help with this topic.
I'm a huge fan of the synthetic clay bar kits. Every time I use an actual clay bar, I end up with more marring than with the synthetic products. I think this is because debris becomes embedded in the real clay, while the synthetic product relies on the lubricant to remove debris and flow away from the synthetic surface, but not completely sure. This isn't one of the best, but I use
https://www.amazon.com/gp/product/B01KWP6HD6 and immolube, which I guess is Claylube now from carpro. It's crazy slick, and very quickly encapsulates anything removed from the paint.
If this is your first time claying a car, please know that any kind of claying can introduce marring regardless of how careful, how often you kneed the clay, or how much lubrication is used, which may leave you less than satisfied. Harbor freight sells DAs that are very much good enough for resolving that, and your local parts store probably carries NuFinish or Meguiar's scratch-x and pads that would gently level those scratches without leaving hazing before sealing. The two mentioned products are not abrasive enough to cause damage if you follow one of the many youtube videos for using a DA, so be assured it's something you can handle.
For finish/sealing, Averything's suggestion of turtle wax hybrid ceramic is a great choice and easy to find at local parts shops. Meguiar's has a similar product that I've had luck with as well. When applying the ceramix wax sprays, it can sometimes come out clumpy, so I keep a spray bottle with distilled water nearby to help dilute and distribute clumps and use one microfiber as a distributor of the ceramic wax for the whole car, and a couple more dry microfiber towels to remove it.
Good luck, and post pics when you're done!