To cancel a team, you need to choose not to renew it for next season. This is under the office tab, under manage renewals. To start a new one in a different world, use the dropdown on the right hand side, join another world.
By joining another world, if you haven't played in it before, you will need to start over a Div. 3.
There are not options to simply cancel a team midseason or transfer from the same team across worlds unless something has changed that I don't know about.