Here's a question. Is it advisable to use a clay bar if you are not machine polishing after ? Will the hand polishing the OP is going to do remove the marring from the claying stage ?
Get yourself a Pressure Washer as your first investment I would say, it will make the rest of your processes after so much easier, I would go for a Nilfisk C110 or C120, you can get them for well under £100. Great reliable machines with metal pumps ! We had a C120 for years and years and the only reason why we now have a C135 is that by dad drove over it by mistake and basically squashed it to death, otherwise it would probably still be here now. packs alot of punch for a little thing, and realistically for home use, its all you will really need for your car.
As to what products to use, until now I have not used a machine before, so its always been by hand, as mentioned above Bilt Hamber cleanser polish is good and so is Auto Glym Super resin polish. Also that new Turtle wax ceramic polish and wax is supposed to be pretty good and it will leave the protection after too, again if you want to protect that, then their ceramic spray coating as a protector is supposed to be pretty nifty too.
As for mine, I chop and change alot, but I chemically decontaminate at the moment and then have BH cleanser polish topped with wowo's crystal sealant which I think is great and both pretty simple and non back breaking to use.
Some suggestions below, but not restricted to, to give you some inspiration. Obviously this is just my opinion only and I could write you a list 50 pages long of products, but these are just a few that spring to mind that I dont think you can go wrong with.
https://www.bilthamber.com/surfex-hd - All purpose cleaner, that can be used as a pre wash and wheel cleaner based on dilution - Pretty cheap too
https://www.bilthamber.com/auto-foam - I find this more effective through a pump sprayer as a very good pre wash
https://www.meguiars.co.uk/shop/gold-class-car-wash-shampoo-conditioner - Got this when you could get it in Costco in a Gallon for peanuts, actually find it to be my go to Shampoo now. Lots of suds and lubrication.
https://www.bilthamber.com/korrosol - Iron fall out remover
https://www.amdetails.co.uk/am-tar - As it says on the tin
https://www.turtlewax.com/our-produ...rtle-wax-hybrid-solutions-ceramic-polish-wax/ - Not tried this yet but has some rave reviews online for a one step polish
https://www.turtlewax.com/en-gb/our...tle-wax-hybrid-solutions-ceramic-wax-coating/ - Not tried this yet, but can use on paint glass and plastics apparently so very versatile and very good protection too for the money.
https://www.bilthamber.com/cleanser-polish - Very good
https://www.wowos.co.uk/shop-2/wowos-crystal-sealant/ - Very good, use it on the paint and wheels for long term protection
https://www.bilthamber.com/auto-wheel - Very good - Similar to Korrosol above
https://www.cleanandshiny.co.uk/products/zaino-z16-perfect-tire-gloss - I love this stuff, I always come back to it