No question is dumb. This forum is all about helping others and making sure we have aquarists to keep the hobby alive. A well established well taken care of tank can last forever. My LPS
has a brain that they have had for over 25 years.
As for the skimmer you should have or need to get a valve for the tubing
Usually they only have one nipple but any type will work. If it's just the hose then placing tour finger over the end will cause the bubbles inside the chamber to stop. You can get this from a LPS
or ever big box store like Petco, petsmart, and possibly a hardware store with a low pressure air tubing section. Really all it does is control the amount air allowed to enter the chamber. My skimmer is about as cheap as you can get and I get great skimate from it. It took a little bit to get the control right, but it's. Labor of love.
Here is my skimmer
Amazon has them too
Fish are people too!!!