How to create my own chronograph rattrapante backround

I am able to find already made backrounds, i am trying to figure out how to make my own.

If you mean how to create an image that will work as a background then I would suggest a program called “Paint.NET”: https://www.getpaint.net/

It’s one of the free clones of Photoshop.
I personally prefer it (over eg.: Gimp) because it feels intuitive (at least for me).

But no matter what program you will be using, try Googling a tutorial for it: http://lmgtfy.com/?q=paint+net+tutorial

The best way is drawing it out by yourself . You can use illustrator , coreldraw and photoshop.