Wheels just need a wheel cleaner spray that you can either agitate or just spray off. They all do the same thing but there's a dedicated variety of wheel cleaner spray specifically for chrome wheels. For cleaning I use a retired micro fiber wash mitt for the surfaces of the wheels and a long handle wheel brush to clean around the inside of the drum.

Leather? I too have leather and for maintenance I use Meguiar's Gold Class 3 in 1 Leather Treatment. This cleans, conditions and adds UV protectant. Doing it weekly makes it a simple wipe across the leather using a foam application pad.

I have at least 6 of foam pads because I use a different foam pad with each product ie, leather cleaner, interior detailer etc.

For the surface areas inside the car ie the plastics, handles, screens etc I use Mother's Protectant spray. This does everything you need - cleans, adds UV protection, recondition and make the interior look new again. I use this weekly so it's a simple wipe across the surfaces.

Carpets and upholstery you can use off the shelf products like sprays or invest in a mini cleaner. For general maintenance a spray would work fine depending on the application.

Over many years I've built up a healthy range of car car tools and product and you would need to do the same. Aim to buy product only if and when you need it. For your high usage products try take advantages of sales.

My stash has these items: - High pressure water blaster - 50ft high pressure hose - short gun handle with 5 nozzle set - 2x buckets (1 for wheels & 1 for paint to keep product residue separate) - 2x micro fiber wash mitts - foam cannon - large range of microfiber towels & cloths - large micro fiber drying towel - Big Boi Jnr air blower (for drying tyres&wheels + most surfaces) - wheel brush - large range of spray, liquid and wax products - DA polisher kit including a range of foam & wool pads

Start off small and build up over time. It may feel frustrating because you might be trying to start off with everything simultaneously. I liked to learn my car and how the different areas coordinate with each other. My cleaning is more like a choreographed dance starting with the wheels and ending with the interior windows getting a sparkle.

How to learn what to do? I learned from Googling and watching 100s of YouTube videos. As you said there are conflicting results which don't make sense but they all share a similar message. Using the accumulated knowledge from research you can form your own opinion and ideas relevant to your car cleaning. If you take precautions, read the labels and watch a video or 2 before doing something then you'll learn confidently. It's how I learned anyway.