Is that a hot tub up top, or a splash pool? I'll call it a hot tub for now.
Pipes on left side are coming from your pool, and are pumped into your filter. Just guessing, but the first valve may be the hot tub drain (off), and the second two are probably from the skimmer and a main drain of your pool. Guess just based on proximity to each other, but that could be wildly wrong. I would verify each valve and label the pipes accordingly so you remember - you should be able to feel the suction of each when on/off, or there's also some type of dye that you can use.
Pipes on right side are going back to your pool and hot tub after being filtered. You should be able to experiment with these more easily to see which valves correspond to which return.
For the cleaner, first verify your system pressure (dial on filter). Do a backwash/rinse, and see if the pressure goes down. Next, verify you get suction by using your hand on the skimmer - you should be able to feel it. If so, then attach the hose back. If the problem is not enough suction, then you can close the main drain to allow more pressure from the skimmer.
Next, go over to the pump and make sure it's still running and hasn't lost its prime. If it sounds really rough or clearly has a big air gap, there was likely a lot of air in the hose when you attached it. Next time, you can submerge part of the hose first to ensure not as much air gets in the system.
If the pump is running fine and starts pumping water, next step is to inspect the hose. Pull it up out of the water a bit at a time, leaving the cleaner in the water. You should be able to feel the water moving inside the hose, and there should be no leaks in the hose.
Hopefully, it's something simple like this on the plumbing side. The unit itself could also be damaged, though I'd suspect that's rare (not a ton of parts in these things).
