An important factor when choosing a VPN is the location of servers in countries outside the 14 Eyes Alliance. But don't get fooled. Some info: What Are the 5-Eyes, 9-Eyes, and 14-Eyes Intelligence Sharing Alliances? Why Edward Snowden is urging users to stop using ExpressVPN? Is Kape Technologies a Trustworthy Company? My advice is to rent a bulletproof dedicated server in Iceland(anonymous payments) and to install WireGuard on it.
Setting up a VPN for file sharing can seem daunting at first, but don't worry. There are plenty of tutorials out there to guide you through the process.