I have a computer on a small network, so my ip is 192.168.2.100.
I am trying to get my real ip. I download the no-ip client but that just seems like a lot of trouble
No, there's not really an easier way. Your computer really doesn't know the public IP it's behind -- there could any number of layers of NAT between it and the public internet. All it knows is that it receives messages at 192.168.2.100, and sends outgoing messages through the gateway at 192.168.2.1. It has no idea what happens after the packet hits the gateway.