Where do you see archive or what do you call meta or archive on the screenshot ?
On the right side of the page, I want to remove them and make a full widht-page. I was able to do it in normal pages, but I cant do it with buddypress pages since they dont appear in the Pages section..
Read here for a solution:
Full Width Profile Pages
Note that it exist other solutions, perhaps more complex or difficult, in function of your experience with theming.
I’m a newbie and I don’t know how to do it. I just paste this in the style.css, right? But it works only for 1 buddypress page, how do I make it for every BP page?
Was explained somehow:
You can do that by CSS from within your child-theme style.css
As it is not only BuddyPress css, but also dependent of your theme, you have to check for the correct classes and id’s to use.
completed by:
On each BP page is a page-id-{number}. You need it to define the style for this page only.
Sorry, i can’t do more for you. It is to you to learn and understand what is explained. Or to hire a dev if it is too difficult.