Hello and welcome:)

To answer your questions:

1. Umm, yeah, you'd have to make an account on hexbear or any other instances that federated with them, but hexbear shut down few weeks ago, due to a domain expiration (I think eventually something new might be created)

2. It's not exactly necessary to make an account for every instance, but you could have a few accounts on instances that federate with instances you interested in. I'm on mander which federates with almost all instances, apart from meta's threads and maybe one more I think. You could check the ideas surrounding an instance before making an account to see if it suits you.

3. Yeah, to check the instances an instance federates with, go to "instance-address"/instances, where "instance-address" is the url of your instance. For beehaw that would be https://beehaw.org/instances

4. Ayy, I too use Thunder:)

Hope I helped😄

I want to post to Hexbear’s DIY community – as far as I can tell, it’s the biggest one by far. However, Hexbear is not federated with Beehaw. That means, I’d have to create a seperate account for Hexbear. Correct?

Yes that's correct. If an instance wants to separate itself from another the only way is to have an account with an instance that is federated with the one you want to post on.

Do you 🫵 make an account for every instance that you’re interested in, which is not federated with Beehaw?

If you want to that's an option. It might be the best option as federation between instances can change in the future. Sometimes it might be a better to help the other communities grow by giving them the content. It's up to you.

Is there a way to see which instances are federated with Beehaw? The /search/ page is helpful, but I have to search manually, whereas I’d like an overview type of thing.

https://defed.xyz

Do you use an app on Android? I like Thunder, you?

Thats up to you what you like best

Welcome to lemmy! Glad you found us. Make yourself at home. And it was a great first post!