Does Libre save automatically? Is it live with other users?
Does Libre save automatically?
It can be configured to do so. Have a look under Tools > Options… > Load/Save > General. The related help page is here.
Is it live with other users?
Not sure what you mean by this. If you are asking whether a single file can be edited by two people simultaneously and have the changes from each user instantly displayed to the other user, then the answer is no.
With the spreadsheets it is possible a live share only for data. Editing formats or objects like charts are not available in share mode.