Linking custom post types

First off, I am sorry but the search is not helping me much, I think I found a bit of the solution here but not completely. I found this do not knoe if it is what I am looking for: https://iworks.pl/firma/klienci/o/onTheGoSystem/types/docs/filters/wpt_field_options.html
Here is what I want to accomplish:

I have two custom post types, say “Brands” and “Products”. When I create a new product, I want the post to feature a radio button list that lists all the Brands so I can pick which brands produces that product. That is one thing I need to do on the back-end and I can’t figure out how to dynamically load the Brands into the Products.

Then I want to show all brands on the front end and while doing that, lists all the products of that brand below, so it must be something like a linked wp_query that calls the brands first (I can do that) and then shows all products for each brand like this:

Brand 1
– product 1
– product 2
Brand 2
– product 1
– etc…

I would like to get a hint of how to go about this since it would make working with types more rewarding.

On a side note, I write my own PHP pages and use shortcodes, not the WYSIWIG version.

EDIT: changed typo and added link

https://www.ads-software.com/plugins/types/