This will show you how to make a moving thing that moves forever.
First place a piston 1 block high off the ground.Then place a slime block in front of that and 2 more pistons in front of that.
Destroy the piston closest to the slime block and replace it with a sticky piston.It has to be facing the slime block.
Place a slime block coming out of the piston facing nothing and then red stone blocks on both slime blocks.
Place a red stone block on top of the sticky piston.Then destroy it and it will start moving.
If it works then you've finished.Congratulations!