To get to the end cities you'll need some epearls and to go to /warp end, follow one of the staircases up and to where the bed rock is with the little portal inside and throw an enderpearl in it, you'll be in the end were the end cities are!
Hey there
As Red mentioned /warp end takes you to the end where you can run up the stairs to find the ender dragon area. If needed /warp grinder has an end portal and /warp phantomvalley does as well
