Your problem is that you have not bothered to learn how to use the site. If someone posts messages or pictures that you don't like, you can click on their name and select "unfriend" and you won't see any more material from that source. On the left side of your "Home" screen you see "News Feed" and "Messenger". You can click there and find the tools menu and control what you see. Such "Tools" menus are scattered around, so you have to be aware and look for what you want. If you post a comment, there will be either a pointy thing or three dots to the right. Either gets you a menu to edit, delete, or some other things.
The same goes for programs. Every program you use has a tools menu. If you use tools a lot it will be a toolbar across the top of the screen. If you rarely use tools it might be hidden. In Windows you can click "Start" and select "Control Panel" and that gives you a menu of menus to control everything the computer does. You can right click anything and most of the time get a menu for that specific item. For example if you right click the desktop you have the option to rotate the monitor image in some graphic cards. That allows you to have an image that is high instead of wide, by turning your monitor. You don't need to memorize all these things, just be aware that they are in there. Then you can claim to know how to operate a computer at the beginner level.