No, it's fine! Not stupid!
you put the vacuum end in the water of your tank, you put your thumb most of the way over the end that it will be coming out of, put your mouth on it, and SUCK!
As soon as the water starts coming down the tube put it straight into the bucket and it should start the vacuum going
There are several ways to start a gravel vacuum, but I always had trouble with the other way where you fill the vacuum end with water, tilt it up, then put it back in the tank..never worked for me. Of course, there's always the risk of getting tank water in your mouth....but...haha
You'll get the hang of it
Did I explain it well enough? I can probably find a video if you want and link it