How do I change who you play as from the default pawn to my imported character?

I have a school project due in 2 days so I need help immediately. I had a few weeks to teach myself how to use unreal engine 4, blender, and makehuman by myself. I am trying to change the character you polay as from the little flying ufo that shoots round discs to my imported character. I also want to make my imported character jog and shoot discs at enemies. I made the disk in Maya and it will be the players weapon. I also need to make an enemy spawner that spawns 6 waves of enemies and has a final boss. I need the enemies to have health and the player have health also. It would be FANTASTIC if somoene could help me on all of these as I have extreme little time. thank you so much.