That's a mighty fine machine you got there! Also, this is the first drink you made with it?? It looks professional AF!
What you're looking for is called a knockbox. You can buy one, they're not super expensive (€5-€20), but you can also make one, which is a lot more fun! I used this guide a while ago to get an idea, then used a plastic base, rubber hose, and construction bolt, because that's what I had on hand.
Edit. I see someone else posted a dope photo of a diy one, too! This is a fun hobby, so just get creative and have fun!
Edit. There's a lot of "to make the best espresso you must X" or "the best espresso must look like Y" types of near-gatekeeping things out there, but take them with a grain of salt as suggestions and nothing more. The best espresso, is the one you love.
Edit. Lol "mess". I was looking at the background, and thought that it's really nice how neat people keep their espresso stations, and that I should too hahahahaha!!
I'm sorry you're having a hard time. Not that it helps, per se, but know you're not alone. This Internet stranger is pulling for you, mate!