My Custom Map ive made cant be played with race.

Hello all, I’m sorry if this is obvious knowledge already but I don’t know how to do this. I have made a map in forge. Its a race in the sense that I want the first person that reaches a certain point on a map to win. I have made the map and now I want to create a game type for it so that I can play the map in custom multi-player. How would I be able to do this?