Coating is useless untill base is properly prepared.
You would have to use a polisher and it should be da as you are a beginner and should have proper pads.
First you should wash your cars observing all details
Next you should do decontamination by a clay media and iron remover
Next you should try to use 2 in 1 compound + finishing polish as 1 step as doing separately will be a hell.
Next you should do an ipa wipe.
Then apply coating and let it cure in an shaded area for almost 24 hours