Is there device which would give me hardware VPN? I heard that I can somehow install VPN on the router, but I would like to have it not on the router, but only on one cable (for cable connection PC) between the router and PC.
raspberry pi. config it to run VPN or even tor proxy and connect by it (as gateway between your PC, router and Raspberry Pi)
There is no “hardware VPN.” It is always software that provides the VPN features. You likely mean a site-to-site VPN tunnel. This means that you don’t install and configure the VPN software on every device, but on the router/firewall of a network. For example, this image shows a site-to-site VPN tunnel between router R1 and router R2:
This depends on your router. Some consumer routers come with native OpenVPN support; others don’t support OpenVPN at all. In corporate environments, you would rather use IPsec than OpenVPN. Besides, there is WireGuard as an upcoming solution.
Do you want to configure a local VPN tunnel between your local PC and the local router to protect your local network traffic? For this, there are other approaches like configuring a separate VLAN (virtual LAN), or using IEEE 802.1AE (MACsec).
I would need something like additional device between router and PC, on which I would install VPN - this raspberry seems ok, but question is how much it is complicated/expensive.
Regarding configuring virtual LAN etc. - this sound complicated, I feel some 100x Linux commands in the air out of which no. 98. entered on 3rd day of configuration will not work. Also, it seem I would need to do separately on all systems on local PC (I have a couple, including liveCD ones, that is one of the reasons making VPN outside would be easier).
What do you want to achieve? I still don’t get it. Do you want to set up a local VPN server to encrypt your local network traffic in your LAN, or do you want to set up a VPN server to remotely connect to your home network (e.g., connecting via the internet)?