Which type of VPN to choose (and how to set it up)?

Question

VPN

Good. Please do not scold me much, but in this case - a teapot. Full.
To the point. What do you need. On VDS I want to raise a VPN server for personal needs. Actually the needs themselves: to unite PCs located behind NAT (both behind cellular operators, but different) into a local network, remove the speed limit on the phone (the operator does not need to be introduced) + peace of mind for data in public Wi-Fi, the girl's access to her series without restrictions from her provider.
An attempt was already made to set up OpenVPN (On Debian), it all ended with the fact that the PC did not go to the network, only a torrent went to the phone (the browser did not see the network), while connecting using the phone’s login / password and after the PC, the phone crashed. If so, everything should work at the same time.
Actually, tell me what type of encryption to use, what commands to enter (preferably just copy and paste). Again, this case is a bit of a teapot.