How to add a Brands

I ask you another thing, I would like this item you see in the attachment to reach the page containing the products of that brand depicted but unfortunately it gives me a 404 error, what can I do?

I would also need to know after going into the products by brand how to insert the filters

Thank you very much, is it also possible to have the purchase invoice or a document that I can record the purchase?

I fixed the brands that lead to the page with the products of that specific brand, but now I would need the sidebar or even better a small drop-down menu with filters.
For example, I go to a certain brand but I only want to see the chairs.

I leave attached the image of the paragraphs and titles found on each category and product shop page, but I can’t remove it in any way, can you tell me how I can do it?

Subsequently in the second attachment you will find this “sidebar” in the shop where the product filters should appear but practically by inserting more than one, it only shows the first and I would like to remove this image but without any success

The sidebar with filters in mobile mode works perfectly.
From desktop, however, once opened it is as if it were disabled and I don’t understand why

As you see the last screenshot I sent, you’ll notice that as soon as I open the sidebar everything becomes dark gray and unclickable

I have inserted the brand filters in the sidebar but once the brand is selected they are not filtered as they should, why?