I am planning to wash, clay, seal, and wax my car this weekend. For white cars I'd recommend adding a chemical cleaner too. Either use a sealant with a chemical cleaner formulated into the sealant, or use a dedicated cleaner.
Cleaners strip the paint and remove light imperfections (water spots, light tar, road film, etc) and keep the paint as white as possible (think whitening toothpaste for your teeth).
Detailers Poli-Coat Paint Sealant, Meguiars White Wax, Klasse AIO Polish, Meguiars Mirror Glaze #20 are all examples of sealants cleaners. All of these are non-abrasive too, so your not removing any clearcoat. If you start to see swirl marks or light scratches down the road, then you can look into an abrasive cleaner sealant product (like XMT 360).
OR you can go with a dedicated cleaner and a dedicated pure sealant.
Typically you get better results when you use dedicated products, but it does take more time. I like to stay in the same family of products, so if you want to use Collinite #845, use their cleaner first (Collinite Sapphire PreWax Cleaner #840).
Wolfgang Paintwork Polish Enhancer, P21S Gloss Enhancing Paintwork Cleanser, Pinnacle Paintwork Cleansing Lotion, Dodo Juice Lime Prime Lite Cleaner Glaze and BLACKFIRE Gloss Enhancing Polish are all examples of pure cleaners. Wolfgang Deep Gloss Paint Sealant 3.0, Klasse High Gloss Sealant Glaze, BLACKFIRE Wet Diamond All Finish Paint Protection, Chemical Guys JetSeal 109, RejeX Paint Sealant, Menzerna Power Lock are all examples or pure sealants.
Personally, I'd go with either Wolfgang Paintwork Polish Enhancer Wolfgang Deep Gloss Paint Sealant or Pinnacle Black Label Surface Cleansing Polish Pinnacle Black Label Diamond Paint Sealant. Klasse AIO Klasse High Gloss Sealant Glaze is a super shiny combo too for the price.
Also, make sure you're applying trim sealant to any black plastic often. Contrast is king with white cars. So keep the white white and the black black for best results. Don't let the black fade or you'll with you started protecting it sooner.
I almost forgot to mention CarPro Hydro 2.
It's a spray on/rinse off sealant so its super easy to apply (as long as you don't apply too much product and have a strong stream of water to rinse it off) and looks amazing. It's a forum favorite. Two different coworkers pulled into the parking lot and their rides seems extra glossy. I asked them what they used: Hydro 2.
I love taking care of my car, it is almost a sort of zen moment for me.