Is it possible to do this with PiVPN or Wireguard?

I’m new to DietPi and have a RP4 running the latest DietPi with PiHole and Samba installed, using a USB 3 external drive as a share which is all working nicely.

There are a few things I’d like to do with the Pi, just wondering the smoothest way of achieve them and if it’s possible.

Firstly I’d like to create a VPN tunnel between my Pi in Canada, and my Windows 2012R2 Server in Australia. Either a split-tunnel so I can leave the VPN connected at all times and all traffic destined for the Windows Server goes over the VPN while all other traffic goes via the local internet connection. Or a VPN that can be easily turned on and off when I need to send files across to Australia without having to SSH to the Pi, perhaps a web interface control to enable/disable the VPN connection each time I need to use it?
A VPN client in Australia will have to be installed to the Windows Server, I do not have a VPN capable router over there, any recommendations on a Windows Client?

Secondly, I’d like a VPN client installed on the Pi which is always running which I can login to from my Android phone or Windows PC anywhere in the world, so I can administer things on the Pi’s home network remotely.

I’ve heard of PiVPN and Wireguard, can these services do what I’m looking for and can you recommend how to set it up or point me to a guide?

Very new to this and want to get it right first time, thanks!

Ahmm is this a duplicate?