Same. I love the idea of being involved in the software community, but find it intimidatingly difficult to know how to "break in". Plenty of the names dropped here are people I admire and follow on social media, but I would think myself terribly rude to introduce myself to them as I'm just an irrelevant developer.
I have something of a following (newsletters, social media), gave two talks at PyCon, and even had a booth advertising my training services. So at the risk of sounding like a total egomaniac just for responding, let me say a few things:
1. I absolutely, positively love meeting new people at PyCon, regardless of their background, level, etc. I learn new things from just about everyone I meet, and that's a huge part of the fun for me. I'm frustrated that I don't get a chance to just meet and chat with more people during the conference, and actively try to eat meals with people I don't yet know so that I can get to know them.
2. Part of the greatness of the Python community is that we realize other people, regardless of their fame, are just that -- people. They were unknown at some point, and people were nice to them. So they'll probably be nice to you, too.
3. Every community has jerks, Python included. If someone famous isn't nice to you, then just ignore them from that point on, and concentrate on the numerous nice people. It's not worth getting riled up or upset about it.
Al Sweigart, Eric Matthes, Reuven Lerner (also in this comment section), and so many folks who've made blog posts, books, code, or something else that's inspired you really do love it when you tell them. I know I'm always please when someone who likes something I've done introduces themselves and says so.
We're all just people. Meeting someone in-person who enjoys something you've done is enjoyable for nearly everyone. Fawning is a bit much, but a "thank you for what you do" is really lovely.
If you're not sure how to "break in": keep the Pac-Man rule that's often embraced at PyCon in mind. If there's an open spot in a huddled group or if the group seems to notice you eyeing them and make a spot for you, join the group. Feel free to just fish bowl the conversation. Most of the time I've seen this happen, eventually someone chats with whoever just joined the conversation. Don't be afraid to either keep fish bowling or walk away if the conversation isn't what you were expecting. Either are acceptable.
You noted that you're afraid of being rude. That means you're exactly the person most folks would love to chat with since you're probably both humble and kind. :)
You shouldn't feel that way at all. I don't think I've ever had a bad experience meeting people at a conference. It has actually been the opposite. Many people are there to make connections (and have their own doubts as well). You might be surprised at how receptive they will be. Also, many conferences actively promote inclusion. See the "Pac Man Rule" attributed to Eric Holscher which was referenced at PyCon US. https://www.ericholscher.com/blog/2017/aug/2/pacman-rule-con...
