No stupid things, it can be pretty complicated.
There are two things you can setup on your router:
"OpenVPN Server": For when you want to make a secure connection over the internet
TO your home network. In that case, the device you want to connect over VPN (like laptop or other mobile device) is acting like a client.
"OpenVPN Client": When you want to connect over a secure connection to a VPN Server on the internet (like ExpressVPN)
FROM your home network.
To connect your laptop through WiFi on your home network, you don't need VPN and I think connecting to the server running on your router works only from WAN (internet). Your data traffic over WiFi is encrypted by WPA Encryption, so no need to protect is with VPN.