Hi DamageIncM, Welcome to 7F,
To secure your network, choose WPA2-AES from your router, then all wireless computers will be prompt to key in the network key to be connected to your secured network. If you need a detail guide on how to do this, please provide the exact Make and Model of your Router.
First of all, is there a way to setup a connection in a secure manner?
As for the Port forwarding concerns, you will also configure this in your router, if there are Apps/Programs that doesn't work properly then you'll have to port forward Port Nos. for these to function. I use Portforwarding.com for this.
Your router must have DHCP enabled, so that Dynamic IP (or Auto IP-An IP address that changes every time) will be distributed in all the computers in your network. Static IP or Manual IP is a fixed IP and stays. The recommended settings in your router and computer is DHCP.
Hope this helps.