The thing about the phrase, "There are no stupid questions" is that it doesn't feel true to the person who needs to ask but it feels incredibly true to the person who can answer.
To expand on this a bit, we're surrounded by the idea of "everybody knows" and we're made to feel ashamed of our lack of knowledge. If you don't know something, it can feel like you must be an idiot to have to ask someone.
But the people who know the answer? The ones who learned it before you? They used to be where you are now. The know what it's like not to know the answer, and they know it's something that you'll struggle with if you need to learn it on your own.
Asking for help isn't a sign of weakness. Not knowing something isn't a sign of stupidity. Give the people around you the chance to share their knowledge with you and both of you will benefit as a result.
I struggle with this on a daily basis. I have since I was a little kid and I was labeled "gifted", and everyone expected me to do so well that I started being afraid to ask questions because....what if someone found out that I DON'T KNOW?!??!
I used to have this struggle, but the way I personally manage it is by asking questions all the time. Idle curiosity? Ask a question. Need help with something? Ask a question. Can't remember that thing that happened that one time with that guy- you know the one? Ask a question.
People see me as curious and engaged with the world, not stupid.
I also do the work the answer the questions that I can answer on my own. I'll look things up or check with my usual sources and then I'll reach out and ask for confirmation. This makes me seem resourceful but also careful.
Don't assume what someone else's interpretation of you is going to be. Odds are decent it's going to be more positive than your interpretation of yourself. And if they do end up thinking you're an idiot? Well, is there anything more satisfying than proving someone wrong.
Coming back to this one because one of my coworkers booked a meeting with me on Friday because they needed help figuring out what questions to ask for a project they were just starting up. They explained the project briefly, and I rattled off 15-20 questions off the top of my head and they just couldn't get over the fact that I was able to ask such good questions without even thinking about it.
Asking questions is a skill and the more you do it, the better you are at it. To the point that other people will ask you how they can do it too.