Ask HN: Whats the best way to secure a NAS device for outside access?

I'm looking to setup a NAS device that can be accessed by one remote person. I was thinking the easy way to do this would be to configure home office VPN appliance that has good performance. I have been out of the security field for awhile, and I'm more of a desktop support guy anyway that has some, but not a lot, of security knowledge. My goal is to host files remotely from my NAS device. I dont want to put my device on the net as I am sure it will be hacked, so I am looking for VPN appliances to fit the bill. The last time I worked with VPN related technology (15 years ago) they were slow has hell on the processor end and I am thinking that has improved somewhat. I have one person that needs to be able to read and write PDF files directly to the NAS and I am wondering if anyone versed in this field can point me to some equipment that will fit my use-case and provide that user with fast file system access over a VPN tunnel using an appliance device. I don't have a lot of time to configure and support my own custom device. I currently have a NOKIA BGW320-505 Gateway device with a local provider that supplies ATT's fiber service at 50mpbs Down and 10Mbps Up with a Gigabit Switch. I'm looking for the best way to get reliable and secure VPN capabilities and am thinking of an independent VPN device [like this one](https://www.amazon.com/NETGEAR-Insight-Managed-Business-Router/dp/B08GL497XL), but I am open to suggestions. Thank you for your time in helping people find good security solutions.