how can i make the canvas to fit perfect with my iphone ,ipad resolution ? without showing me small buttons ?
There are many resources to answer your question. Have a look at the Unity tutorials here. look at the generic modal panel tutorials also, as the live training videos on it supply great resources for creating panels and resizable windows. The videos also give you a general idea of good practices on setting up your UI. The generic modal panel may not be what you’re trying to do, but it could possibly answer your problem. Tell me if you need anything else.
You can set the canvas to scale with the screen and then the canvas will scale with your screen size 