Ilona Please open the ports on your router which you need for the VPN:
VPN Server Ports:
PPTP TCP 1723, Other 47
OpenVPN UDP 1194
IPSec UDP 500, UDP 4500
How to open the ports is explained here. I would also assign an internal fixed IP to your computer, which needs the VPN. You can find the instructions here.
Greetings
Daniele