Hi Mel, within that Profiles folder, there usually are two -- possibly more -- subfolders with partially random names. In each subfolder, click in and look for another folder named bookmarkbackups that contains automatic backups created by Firefox. The files have the creation date in their names, so you should be able to identify which are the most recent.

You can copy/paste a couple of files to the Desktop for easier access, then check the steps in the following article to restore them to your new installation. On the Restore menu, use the "Chose File..." option to point Firefox to one of the pasted files on your desktop.

Restore bookmarks from backup or move them to another computer

Success?

Thank you so much!! This worked!! I should have asked about finding everything I lost like passwords and auto fill.

Hi Mel, your old logins file is named logins.json and the companion key file is named key4.db. You can copy/paste the two files from your old profile folder to your current one to replace the newer (emptier) set. Here are some general reference articles:

(1) How do you find your current profile folder: Profiles - Where Firefox stores your bookmarks, passwords and other user data

(2) What files have what data: Recovering important data from an old profile