Please understand the topic/post moderation process before disabling it. It's made for you and for your forum protection and it only works for new users not for all.

wpForo 1.2.0 comes with Spam Control functions. Also we recommend to install Akismet for more protection, and for making wpForo Spam Control more intuitive.

Only new users' topic and posts are being suspected for spam and go for moderation. New user is based on minimum number of posts. You can manage it in Dashboard > Forums > Tools > Antspam admin page.

If you test forum with fake users and fake content you'll always see those topics and posts as unapproved. Please teast it with real users and real content (don't duplicate them). If you still got many unapproved topics/posts please read this support topic to decrease spam controlling level:
https://wordpress.org/support/topic/new-topics-and-post-without-moderation/#post-8977005

Yeah I understand, but I don't have a big communauty. Also, I have already Aksimet and an other plugin, who restrict the creation of accounts.

Forum spamming doesn't depends on community size. In any case if you’re sure that you don’t have spam problem, you can disable wpForo Spam Control in Dashboard > Forums > Tools > Antispam admin page, just set “No” the “Enable wpForo Spam Control” option.