Can I Access My Mac mini At Home From My MacBook Air While I Am Traveling?

While I am traveling, I would like to access my downloads, recents, and documents folder on my Mac Mini hard drive, and my desktop if that is possible. I am a bookkeeper and I have an external hard drive with sensitive data that I physically take with me. But I do have a lot of folders and documents in those folders on my Mini hard drive that I would like to have access to while I am away. The documents in those folders are not sensitive, but I don’t want them on the cloud.
I would love to be able to open my Mini and have it be just as if I am at home working as usual from my laptop.
It seems like years ago there used to be a way to easily do this using remote access or something like that. It’s not so intuitive now.
I don’t know how to do it, but I can learn how to set up a VPN or something like that if that is the correct way to handle this.
I have a 2018 Mini using Big Sur 11.5.1 with a 120GB hd with about 20 GB free. It is driving two 32 inch curved displays and an external 2TB drive, a CD drive (which is currently not working) and a mic/camera and a couple other USB devices.
I am starting to be away from my desk for two weeks at a time. I travel with my Air and I bring an HDMI to USB C cable and use the large screen tv wherever I am as a monitor. It’s not like having two monitors as I do at home because I can only mirror displays, but at least it is bigger and I can see my clients financial docs more easily. I also bring my external HD with the client-sensitive data on it.
—–
Lynn