What to do if I know conpositions and I can't still apply them in my photos?

You ought, I suppose, to begin. You must know the topic in depth. In any scenario, you will gain motivation from other professional individuals. You understand the scope of their practice to see if emotional health can shift. Thank you!

try writing in english first , then what type of photos , printed or digital . get a decent photo editor like photo filtre , a french and eglish photo editor , it lets you change the background , its freeware . google it , photo filtre and you should get a link to the site .

Depends upon what types of photos you're trying to make.  What kinds are you doing?  You mention locations, so it would seem that you're into landscapes.  With landscapes, you must start with an interesting place, otherwise your job will be a lot tougher...but not impossible.

There are many aspects of composition, but of course not all are applicable to all photos.  For example, leading lines is an effective composition technique, but if you're shooting a foggy snow scene there may not be any lines (literal or implied) in the scene.

Photography is a visual language where composition is like grammar.  You wouldn't use the same style of grammar for a children's book as you'd use for an academic paper on the fundamentals of psychology.  Therefore, the combination of your style and the scene (subject matter & quality of light) will dictate which composition techniques to implement.

To help you figure out what works, I strongly encourage you to study the work of the great photographers in your genre.  By studying the great works, you will train your eye on how to see a scene and which techniques work for which scenes.

You need to develop your own style (tell your own story about the picture in your own special way). Composition rules are only guides to producing potential eye-candy shots. There are loads of them and you can choose which you think will help your individual photo:  Rule of Two Thirds, Leading Lines, Diagonals, Repetitive Shapes, Framing, Contrasts between subjects ( like two completely different kinds of trees in a forest), Recession of Planes for distance, Interesting foreground, blur background etc.   Pick the time of day with care. Golden Hour (one hour after sunrise and one hour before sunset) lights up subjects which reflect their light back to you beautifully. Blue Hour (one hour before dawn and one hour after sunset) is great for cities with buildings and lighting. There is so much out there, just work out where it is and what story you want to tell.

You studied compositions but can't apply? Then apply all of them for every scene you shoot. Sooner than later, you'd get the feel of what works with what and narrow down your choices every time you shoot. If that's too much for you, just go with what comes natural. Don't think. Just shoot. Sometimes, that is all it takes.

Somebody like Margaret Bourke-White could photograph the most humdrum of things and make them look fantastic (although to be fair she also had some amazing locations). Look at work that you admire and work out what they did, how they framed the shot and got the right angle and lighting.