You can't.
If you have windows press f3 if you have a mac press fn + f3
f3
f3+h
just press f3+b and at the bottom of the screen it will say hitboxes shown
You can't.
If you have windows press f3 if you have a mac press fn + f3
Press F3
f3
f3+h
If you are asking about the hight level then you look at the Y: coordinates at the top left of F3
You can either create a map or press F3. Pressing F3 will show you your coordinates, the biome you're in, and a whole lot more.
Simply press F3. It will say the version in the debug info.
You might have pressed F5 in a way that looks like you pressed F3
While in the game, press F3 and it will tell you what version you currently have at the top
just press f3+b and at the bottom of the screen it will say hitboxes shown
You can only find diamonds in the bottom 16 layers of the map. You can find which layer you're in by hitting F3 (or fn+F3 on a Mac); look for your "y" coordinate.