Create advertising blocks

You need to create advertising blocks of 120*600 and 160*600 formats with the ability to switch between formats. The blocks are placed on the right and left sides. The blocks should be fixed when scrolling in place as indicated in the example. These advertising blocks should not appear on mobile devices and do not change the structure of the site. Blocks should not appear on the main page.
Site: Texte caché Example of blocks: Texte caché