Login to your club control panel, click Site Content from the left-hand menu and select Forum from the expanded menu list.
If you have any forums that have been previously created you can delete them by hovering over the spanner icon towards the right of the forum name and click Delete Section.
To prevent the Forum tab from appearing on your website click Settings from the left-hand menu within your club control panel.
After that, click Navigation from the expanded menu list.
As seen on the screenshot below, untick Show "Forum" and click Save in green.