Looks like you’re planning on doing the refurb yourself.
Not necessary to cover the brakes if you remove the wheels from the car, and removing the wheels will make it so much easier to rub them down off the car than while still bolted on. Also, removing the wheels eliminates the risk of paint spray drift onto the car’s surrounding bodywork that could happen if the wheels are painted while on the car. Ensure the car is well supported when the wheels are removed - if your car has a space saver spare and jack, don’t rely on the flimsy jack to support the car (they’re known as a ‘widow maker’ for a reason!). It’d be OK to use the ‘widow maker’ if you only remove one wheel at a time though, as you can put the space saver on while your remove each wheel to work on it.
Ensure wheels are fully rubbed down before any painting, to create a good ‘key’ for the new paint to adhere to and to remove any wax, sealant or other protection, otherwise you may find the new paint you apply peels or flakes off after a few months. If your wheels are badly scuffed in places around the edge from kerb damage, then you may need to fill any rough areas around the rim and sand back to be level with - and the same contour as - the surrounding undamaged areas before painting. Don’t use sandpaper for rubbing down - get a selection of different grades of wet and dry abrasive paper and use plenty of water while rubbing down.
When spraying, ideally do this in a dust and draught-free environment to avoid dust or debris settling on the wheel surface. With painting, less is more - use light coats of primer and paint to avoid paint runs and allow sufficient time between each coat for drying. Rub down lightly between each coat of primer with fine grade wet and dry paper and plenty of water before applying the next coat (don’t rub too hard or you’ll remove the primer you’ve applied!) and wipe down the surface with a ‘tack cloth’ to remove any dust / grit that would show up as imperfections through the gloss / lacquer coats when applied.
After a couple of weeks, polish, and apply some wax or sealant as protection.
Lots of videos on the internet on diy wheel refurbishment. If you’ve not already done so, do a google search on ‘diy car wheel refurbishment’.
Edit; if this is your first attempt at a diy wheel refurb, I’d recommend you get l an old wheel from a breakers yard that you can practice on and perfect your preparation, paint spraying / finishing techniques. IMO, its better to make mistakes on a practice wheel rather than on the real thing.