How do I make the ender portal? I've tried everything to make it but I can't.
If you are trying to create an End Portal in Creative Mode, you must surround the sides of an empty 3 by 3 square with End Portal Blocks, then fill all of them with Eye of Enders. You don't need the portal blocks at the corners, it just looks nicer. The last Eye of Ender placed must be facing IN the portal.
To add on to what kyr said, when you find the End portal in the stronghold, you still have to fill the portal blocks with Eye of Enders with the last one facing the inside of the portal.