how to solve the problem when i run app on physical mobile the app will not fit to the mobile screen in android studio?
Avoid straightly defined values for layout parameters. Always use match_parent or wrap_content components as layout height or width as possible. You can use layout weight attribute to properly manage the layout incase of linear layout.
Your mobile screen is probably smaller that the virtual phone you were using. Design XML such that it fits perfectly in the smallest available template in android studio
If possible try "Constraint layout"