@yourlocalimouto No, you can have as many as you want. Some people only have one, some have a main account and a few backups in trusted servers in case the main one is on maintenance (that's my case), some have a main and alt accounts for other uses (account to post about politics, lewd account, account to post about specific hobbies) to filter content and not annoy followers.
It's really up to preference, much like with servers. Each server also has its own rules for what is and isn't allowed, content warnings if those apply, and so on.

@yourlocalimouto @nerthos you have up to three accounts if you get the gold subscription

@yourlocalimouto gold subscription.

@easthighNerd @hakui @yourlocalimouto That's a soykaf account

@easthighNerd @yourlocalimouto @nerthos three and a half accounts

@yourlocalimouto @hakui @easthighNerd Soykaf is the old pleroma instance set up by the guy that started the project, registrations have been closed for years so having an account there is sort of an old timer privilege, it's just a joke.
You don't need to pay for anything, though you can donate to several of the fedi software projects if you want

@yourlocalimouto @nerthos @easthighNerd no it doesn't mean much really w