Due to the way the Fediverse works, it's a good idea to have at least some followers (even a handful!) before you post interesting content. If you post stuff when you have literally zero followers, that content will usually not be visible outside your server, even if people follow you later.
There's more info on why this situation exists here:
https://fedi.tips/making-your-posts-visible-to-a-wider-audience-on-mastodon-and-the-fediverse
One workaround is to pin posts on your profile, pinned posts are visible to everyone:
https://fedi.tips/how-do-i-pin-my-posts-on-my-mastodon-profile
@FediTips The most interesting posts can be pinned, supposedly they will always be visible at the top of the blog. But this is not certain.
On Mastodon, pinned posts will always be visible to everyone at the top of your profile page.
They will always be visible even if you have no followers.