I assume you're starting from a fixed non-custom ground map like ESD or DS9.
Basically, it means that in order to move from this map to your first actual mission map, you cant leave from 'whole area', or in other words cant just use the beamup button. You have to have the player interact with an object in order to move to the next map.
Sorry if this doesnt help. I dont think im doing a good job of explaining.
can anyone tell me that this means and help me fix it i am ready to publish my first mission
"Your first map transition to a custom map may not use whole map - mission"
You have to pick a door. What this does is allow you to pick an enterence (star system, etc) for your mission. You can't use "whole map" because you need the player to go to an entrence point. However, once in your map, you can beam up or down from anywhere, so you can use Whole Map.
Think of it this way: A mission tells you to go to the Myrax system. Once there you get a pop-up asking you if you want to start the mission. That is what you need for your first transition. What star system does the player need to go to get the pop-up?