Organize forums and topics
From EdTech Help
Forums may be rearranged to change the order in which discussions are listed.
Go to Forums
Select the Forums tool from Tool Menu in your site.
Select the appropriate number next to the Forum or Topic
The numeric pull down menu allows for reordering the Forum, Topic or both. Select the appropriate number for the order in which the items should appear.
After you have placed the forums and topics in the desired order, click Save.