PROBLEME OF SIZE heder LOGO img

You are not using logo image you are using site title as logo so incase you want to change text size. Please add following css into >> wp-admin >> appearance >> additional CSS

.logo h1.site-title,
.logo h1.site-title a {
 font-size:35px;
}

Change 35 to your desired size.

ok thinks

i have other prob

in home page i want to translate this in french but I didn't find her

Please use Loco Translate WordPress plugin to translate the theme into yoru language.

Register Yourself! 

Also try to edit the element from going to page edit, and you should check options there.

Please edit page, and see options of course, and title elements

Hi i try this methode but is not good

I saw you have changed button text, there are few options to allow you change labels but the best way to translate theme is Loco Translate plugin.

I do not find ("OUR COURSES" and "Find best course for yourself!") when searching in loco Translate plugin

Please edit home page then move to courses section , and edit title section there you can change both title and its description , they are not theme strings they are from pages.