There are different ways of approaching microblogs — reading, writing and interacting. You have @s and hashtags in mind already, they’re a good way of finding conversations and engaging with people.

You’ll find users who write interesting stuff about your favourite subjects — you’d want to follow those to get all their updates. That includes boosts/reposts, i.e. posts by others that those you follow share to spread a message. That will also help you find more interesting people and organisations.

Now, interaction. I have come recently to Lemmy from Mastodon instances, and I see quite a bit of difference in the etiquette and forms of socialising. Two generalisations that I can think of:

1. Mastodon and other fedi microblogs were built by users who were fed up by Twitter’s lax moderation of harassment, so they built in safeguards against that; Lemmy was made in reaction to the commodification and heavy handed enshittification of Reddit, but largely expect the same conversations here. They are not the same mentality.

2. On Lemmy, you post a question or thought in a dedicated community to get answers or start a discussion. Each community has its own room where the discussion is centred around one subject. On the microblog side, you might imagine one big, sprawling social club where people mingle and form smaller groups to talk about one thing, then disperse and join other conversations. And sometimes they just talk about their pets or hobbies to nobody in particular.

Sorry, I’m writing this over morning coffee and I know I’m only covering broad fragments of the microblog experience as it differs from using a forum. I hope it helps though.