You need to have the movement in an update function that will constantly update the position of the entities. You can update its X/Y/Z position or you can do some math and have the entities creep up to the player or whatever you need to do.

Look up some ways of movement logic for entities on google or something and watch tutorials on how it works.

If you need more help, and considerably faster results, join the discord. https://discord.gg/Rh7Xfd98BU