Firefox cannot bookmark and has no bookmark bar or menu, even when a fresh copy is downloaded.
One day I discovered that all of my bookmarks had disappeared from Firefox after another family member used the computer. Not only were the bookmarks toolbar and the bookmarks menu missing entirely, but I could not record any new bookmarks. I deleted Firefox and downloaded a fresh copy, but the problem persists.
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Firefox stores 5 days of backups of your bookmarks, so if your "loss" happened within the last 5 days you might be able to restore a backup. If you have used Firefox more than 5 days since that "loss", your backups are probably overwritten.
https://support.mozilla.com/en-US/kb/Lost+Bookmarks
As far as the Menu bar missing, see this:
https://support.mozilla.com/en-US/kb/Menu+bar+is+missing