Help! Need a solution…

I’m a beginner to all of this networking stuff. I want to connect two offices that my parents have, not near each other. I don’t need anything fancy and I’m looking for the cheapest solution. I just basically need file sharing, maybe print sharing, and that’s about it. Just a way to access each other’s files to update records, etc. Someone told me about a VPN, but I’m not sure how those work. If anyone has a solution, please let me know. Details would be good, seeing as I’m a begineer. Thanks for your patience!!