I also want to (1) hide the forums and topics (titles), your contribution worked, although I would have preferred, (2) have the option to hide / show the forums and topics at will.

If this is not possible I will settle for your solution.

However, your solution does not solve the fact that (3) if someone has the URL of the page, it arrives directly without going through the login, How can I fix it?

Thanks.

Google translate

Hi @anibal . This is in addition to Robert's suggestion above, which put's the LogIn code to the Forum Menu, so that when anyone clicks the Forum Menu, if they are not logged in, they will be asked to Login or Register.

The Original Post - this is an Old Post (2017).  I believe there has been several iterations and improvements made to the wpForo Forum Plugin since that time.

https://wpforo.com/community/wpforo-announcements/wpforo-1-6-1-is-released/#post-24863

As of 2019, this is how we can hide specific Categories and Forums. (Or at least that's how I did it). This answers items (1) and (2)

1) Go to Forum Dashboard
2) Forums
3) Select the specific Category (the Blue Bar), or Forum (under the Blue Bar) that you want to hide.
4) Click the corresponding "Pencil" or "edit" icon on the right side of the row.
5) When this specific Category or Forum opens, you will find the "Forum Permissions" box, and the different Usergroups below it.
6) For the "Guest" usergroup - click the drop down menu, and select "No Access" (by default, this shows "read only access")
7) Click the Update button.

And this answers your Item (3)

8) Then copy the exact link to your hidden forum and test it in an Incognito Browser.
9) The page will show "You don't have permissions to see this page, please register or login for further information" - so doing the above steps will hide that specific forum, even if others know or have the specific URL to it. :-) 

Here are links to wpForo Documentation on

Forum Settings
https://wpforo.com/docs/root/wpforo-settings/forum-settings/

and Forum Accesses.
https://wpforo.com/docs/root/wpforo-settings/forum-accesses/

Hope this helps you, or someone. :-) (The steps above is what I've used to hide some specific forums in my forum).

Good luck and God bless you! :-)

If this is not possible I will settle for your solution.

However, your solution does not solve the fact that if someone has the URL of the page, it arrives directly without going through the login, How can I fix it?

Thanks.

Google translate

What do you mean saying "didn't work"?

This change makes the forum home page as a login page. If you don't have other Menus to the home page this will be the only forum home page. user should login or register to see the forum home.

Thanks!

2. Select wpForo Navigation in drop-down menu and open it

3. Open the first "Forum" menu, and change the value to /%wpforo-login%/ , this will show login form for guests and forum list for logged in users.

https://wpforo.com/wp-content/uploads/2017/07/wpForo-make-home-page-login-page.png

Kind regards,
Patrick