Discoverability is trickier on Mastodon. There is no algorithm to bring your posts to the masses. With a net new account with 0 followers, you are reliant on someone on your Local instance seeing and responding/boosting your post to their respective network of followers. You may have luck using hashtags in your post to reach those who have followed those hashtags, but even that I think has minimal effect unless you are using a niche tag that happens to be one that a lot of active folks follow (unlikely?). What this means, is you need to spend some time early on to build out a bit of a network before your own posts have any useful reach. I have a few things I've written up that can help...
On engagement: https://shellsharks.com/notes/2023/09/20/engagement-on-masto...
On building an audience: https://shellsharks.com/notes/2024/06/27/building-an-audienc...
A starter pack with tips and tricks: https://shellsharks.com/notes/2023/10/20/infosec-mastodon-st...