Lost access to WordPress panel

Hi guys,

I m new to WordPress and I really need your help.

I was building my website step by step(in WP panel) and then I got stuck how to find the registration form (for users).

I realized that when I log out, it takes me to Mojo Marketplace black screen that says: I just installed WordPress free at…
First, in Settings(using Classipress theme), I checked : Prevents users from accessing wp-login.php directly

Then I deactivated the Mojo marketplace plugin, but then I noticed that my website under construction is accessible to everyone, and I didnt want that.

So I reactivated it again, and here I lost access to my dashboard. I’m stuck in that black screen of Mojo Marketplace and the Login button doesn’t work anymore(probably because I checked Prevents users from accessing wp-login.php directly)
Please help get back my access to my WP dashboard…
Thanks so much