im new and need help

i just got this mac im new to mac, what i need to be able to do is vnc into this laptop from my home pc. im not even sure where to begin, the problem is this laptop will be going to different areas the ip will be changing any ideas. how do i get the external ip can get the lan ip 192.168.x.xx i really am lost any help would be great
thanks in advance

You can get the external IP by just visiting:

That will report your external IP (near the bottom where it says:Your External IP is:). But if you are behind a Router then you will need to setup port forwarding for either your VNC port (5900) or SSH (22). That website contains instructions for a variety of different Router devices.

You can also refer to the Vine Server documentation for more instruction.