Use Scaling if you want your Screen GUI’s to be all the same sizes on all devices you can. do this by going to the properties of each frames , text buttons and text labels etc. Change the Offset to 0 on fall of them then start scaling them from 0.1 After that you can go ahead an mannually Size them.
Note that scaling alone won’t resolve proportionality issues. Please use UIAspectRatioConstraint and Scale together. I recommend using Scale, reading AbsoluteSize and adding a UIAspectRatio constraint to an instance with ratio property of AbsoluteSize.X/AbsoluteSize.Y