I have a vinyl album recorded through Audacity, one album, files saved in a data folder, 800 plus au files in that folder, but I can’t get Audacity to access these files . I have tried File>Open and File>Import. I can only access one file at a time.
Any suggestions on reading , importing all these files in one action?
You should have an AUP file, which is your “master project file” pointing to those audio files. There is some information [u]here in the Audacity User Manual[/u].
If your AUP file is lost or moved or damaged you can try to [u]recover the project[/u].
Or assuming you still have the record, it may be easier to take 45 minutes or so and re-record it.
And this time, or if you recover, export the audio to a WAV file as a back-up. 
Yes. You double click the AUP file with the same name and it will launch Audacity and open the _DATA folder for you.
This is an Audacity Project.
You need both parts. Can you still find the AUP file?
Once the Project opens in Audacity, then you can do whatever production you need or maybe split the files up into songs for a CD or a Personal Music Player. Audacity makes these music files with Export, not Save.
Koz