Okay So I've Started Making my Fist 3D Game, Can Anyone Tell if i can Import Maps/Models From Other Games Such as Like Weapons From Call of Duty or Maps From Call of duty if Not, Can anyone tell me a programme i can download to Make Maps and Characters and Models?

P.S My Game is based off Call of Duty Zombies So ill want Maps Kinda Like That Not Like Huge Desert Terrains and Stuff