using UE4 Templates

is it okay if I use some materials and blueprints from UE4 free templates and import them into my game ?

Yes, you are welcome to use Epic template materials and blueprints in your projects.

well if for example i want to use the landscapemountains template (mountains as background) and added into my project is that still okay ?

Yes, you are free to use these in your UE4 project