Local machine and Intranet DB up to date data formats - which one?

Hi,
New to Julia : I would like to know what are the first 2 (or more) file formats recommanded to store data, strings/numbers
(Multmedia support not needed):

A) - for a local use, on standard workstation, if a txt text file is enough for Crud operations, I am okay with it…

B) - As for an intranet "small network (such as small business 10 Pcs ) what are my options as of today running a supported DB format…on any Linux distro ?
*(pref. NOT MySQL)

  • Something reliable but as easy to set up as possible (mostly regarding the suggested network DB format)
    crossplateform eventually to run on Lin/Win/Mac.

I havent searched yet to see if Julia does/can also manage restrictive access rules by user/group on a network ?!..

Not looking at any cloud system for now
(unless its very cheap and secured)
…and RGDP compliant !

Thanks for any experience