how to import bookmarks from old firefox

The easier way is to use Sync: https://support.mozilla.org/en-US/kb/sync

Or you can do it manually, Firefox has built-in tool for import/export: https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

It is beyond my comprehension why the hell this new firefox Nightly is pushed out to us the users of the old firefox with out moving relevant data form the old to the new automatically or at least ask us to do it on user sign in. There is absolutely no forcking way I am spending 2 min trying the new version if I have to figure out how to get my data exported and imported... hell the import menu only shows the Edge browser, how about that showed the old version of firefox too....

Firefox Nightly is for test purpose, so it might not be suitable for daily use.

You are welcome to offer your suggestions through: Mozilla Connect/Firefox support https://support.mozilla.org/en-US/kb/what-mozilla-connect