you just screw the cleats to those plates in the bottom of the shoes. looks like you all ready got screws in the holes so just remove these screws and fix the cleats to the sole of the shoe using these screws er… you do have cleats don’t you? they usually come with the pedals and some times with the shoes as well.
once fitted loosely, you need to line them up properly; or you run the risk of discomfort, difficulty in un-clipping in a hurry and possibly knee joint damage.
there will be a utube video out there some where just do a search.