In the fingerboardfamilia section on my forum, I give members links to introduce themselves there but it says 'only administrators can reply' how do i change that?

It is in the 'permissions' at the very top of where you set up the forum. You need to change the prompt to 'members'

To direct you in the exact part mentioned in the above post.
General>Categories and Forums
Click on that forum name
Permissions tab.

Check who is allowed what.