Setting up configurable products on M2.4.2

Hello M2 family. I am not able to wrap my head setting up configurable product for my store. I hope someone here might help.

Below are the setups:

I have an apparel A, with 4 different colours. Each colour has 3 different sizes. Each size belonging to the each colour has different quantities.

That is product A

Colors: white red blue Green

Sizes: L XL XXL, L XL XXL, L XL XXL, L XL XXL

Qty: 2 3 1, 4 9 12 , 10 4 20, 3 5 12

How do I set this up as a configurable product or what is the best option to use?

Also how do I display individual simple products, and clicking on it leads to configurable product?

Is it possible for each colour swatch select in the configure product displayed to show the product colour, and also switch the url to the respective colour?

What will be the best option for SEO purposes as well.

Cheers.