The Disney Monorail is iconic transportation! You cannot take the Disney Monorail directly from the Magic Kingdom to Epcot or vice versa. You will need to change trains at the Transportation & Ticket Center. It is clearly marked, and there are plenty of Cast Members around who will be happy to point you in the right direction. You will not need to go down the ramp and up again to catch the next Monorail.
Learn about taking the Disney Skyliner between Epcot and Disney’s Hollywood Studios here.