Also, to empty the cup do I just pull it off or do I have to unplug the skimmer? The skimmer does not come with maintenance information and I didn't easily find the info from a video search. Thank you for any advice.
Here is a video about your skimmer: https://www.youtube.com/watch?v=NCdl4Xrw90s
You do not need to disable your skimmer when you are feeding your fish nor when you are emptying the cup. You just pull the cup off, dump it out and replace it. I would recommend turning the skimmer off during a water change and leaving it off for about an hour before turning it back on to prevent it from overflowing. To "disable" your skimmer just unplug it.
If you ever want clean your skimmer use only vinegar and water and if you clean the skimmer body completely, it may go through another break in period. During a break in period the skimmer will be a little erratic so, be aware of that when you clean it. Every 6 months or so you may want to thoroughly clean the pump and give it a good vinegar and water bath. Other than that the skimmer should be maintenance free.
Hope this helps.