Hi Mena and welcome to Flarum.
Flarum itself does not actually provide hosting, so we don't have any way to access your forum or its accounts. You may have created an account on FreeFlarum.com (a community project for free hosting) or another host that you've arranged for your site.
Either way, you'll need to contact them directly to get assistance. We create the software, but we don't handle data or sites at all here.
