Some reassurances for people who are anxious about participating in fandom:
+ Fandom is not social media. It's a creative and community-based space where people share in mutual love (and/or frustration with!) a specific text, whatever that might be. The rules you've internalized for social media mostly do not apply.
+ The only requirement of fandom is passion. If you genuinely love whatever your fandom is, that is enough. That's all you have to bring. Fandom is for people who are nerdy and get more attached to things than "normal" people do. This space exists for you to dive deep into your nerdiness. Self-consciousness is the enemy.
+ Fandom is a hobby. You don't have to be good at a hobby, you only have to enjoy doing it. That's all.
+ It's more than okay to lurk for a while. You don't have to immediately plunge into participating. In fact, we used to use the phrase "lurk moar" as a reminder that the best way to learn the culture of a specific community is by observation. Almost all fans have a period of time where they just watch what everyone else is doing before they start to interact with others. Take that time, but also don't let inertia keep you from joining in when you feel ready!
+ The economy of fandom is based around gifts. No one is doing this to make money. In fact, we legally can't make money off of most of what we do (and people should not try). We create so that other people will be able to take joy in something we mutually love. If someone creates something beautiful for you, make something for them!
+ That said, if you don't feel that creative drive yourself or if you don't feel confident enough in your own creations, there is no obligation for you to share those kinds of things. If all you want to do is comment on other people's creations and reblog other people's posts, that's okay! That's still makes you a valuable part of the fannish ecosystem! Don't feel guilty because you can't or don't create things! Some of my most beloved friends and fandom members are people who "only" comment/reblog/etc. Fandom isn't fandom without them! Most people who create do so at least partly for the comments, so by providing them, you're fueling further fannish creativity! You are the gasoline that makes the engine run!
+ Fannish creativity, whether fic or art or vids or whatever, is not content. It does not exist for you to consume in the way that social media content does. It exists for you to enjoy and engage with and react to. It exists to inspire you to create on your own. Each fannish thing someone creates is an invitation to squee with them over this thing that you both love. It's the opening salvo in a conversation. Talk back to the people who start the conversation if you want them to keep creating!
+ You don't have to worry about appearing weird if you engage with older content. There is no such thing as something too old to react to. The creator may have moved on or they may not have, but if you read a fic that's 20+ years old, it is not a faux pas to comment on it (I occasionally get comments on fics that are 20+ years old and it delights me more than I can say to know that something I wrote as a college student is still bringing someone joy so many years later!). If you find a tumblr post that's from 6 years ago, it's totally cool to like and/or reblog it. If you love a show from the 60s or a book from the 19th century or an epic from antiquity, it's awesome to share your love. You may not find people who will engage with you about it--but you also might! There are existing fandoms for things that are decades or even centuries old!
+ Two cakes theory is one of fandom's most important principles. No matter how lowly you think your creative offering is, there is someone out there who will enjoy it. I guarantee it. They may or may not tell you that they enjoy it (I won't lie, it can discouraging to create and not get any confirmation via comments and such that someone enjoyed it), but someone out there appreciated it. I know it's hard, but try not to compare your stuff to other people's.
+ Don't be afraid to reach out a hand. As in real life, sometimes you have to be the first one to reach out. Send a message. Start a chat. Reply on the post of someone who doesn't follow you. As long as you're positive and respectful, 85% of people will be excited that someone is talking to them. 10% will feel neutrally about it. Only 5% will think its weird or intrusive. And fuck those people, tbh. They don't deserve you.
+ Lean into what you have in common with someone else. Find someone who loves that specific side character as much as you do. Find someone who's written three fics for that fandom that only has six total fics. Find someone who has the same very unpopular take on a juggernaut ship as you do. And when you reach out your hand as encouraged in the last bullet point, do it by talking about the thing you both love. If someone gets a message from a stranger flailing about their blorbo, they're going to be excited that someone else loves their blorbo.
+ Stay positive. By this, I don't mean that you can't critique things about your fandom or its canon. You can! You should! But make sure that you genuinely love something about that fandom. That it's the love that's pulling you back in. Pure haterism is a bad way to spend your time and while it might feel good to hate with other people, that's only fun in small doses (and mostly in private). If you do it all the time, you'll become the kind of person others don't want to be around.
+ Small fandoms can be just as much fun as large fandoms. If you find one or two other people who love something the way you love it, that can be more than enough. Quality matters more than quantity in fandom, and in fact, the bigger the fandom is, the harder it can be to have a good experience.
+ Most older/more experienced fans are delighted at new fans finding fandom so long as they make a good faith effort to be respectful. If you're someone who's bashing older people for "still" being in fandom, people will tell you off, and they deserve to. But if you have a good attitude, the vast majority of people will just be glad to have another person who loves the thing they love. We want fandom to continue and to be for younger/less experienced fans to get all the great things out of it that we did. We want our specific fandoms to continue, even after we move on from them. So while you may come across some grumpy gatekeepers, most people will be delighted to have you join them!