Another idea:
You can quite easily see what a force is. You pushing a block on the floor produces a pushing force.
Now, imagine that push, from one place to another, as being made up of lots and lots of little pushes. It's just like imagining moving your arm around in a circle, as making lots of small movements, which added together make the complete circle movement.
The work done (another name for energy), is the adding up of all these little bits of pushing force, from the start place where the block is, to where you stopped pushing the block.
Because you're adding up the force along the distance you move the block, the units change. Force has units of Newtons. Distance has units of metres. Combined together, energy has units of Newton metres. This is the same as the Joule, the more commonly used singular unit of energy.