How do make this game multiplayer friendly?

Hey guys, so I’m a beginner to UE4 and have started following this FPS Series by Virtus Learning Hub. Now, when I wanted to try out the local multiplayer in the game, I noticed that it only shows my player moving and nothing else. One other thing is that when I go over hurting zones, the blood effect is replicated to all players. And If I hit another player with a bullet, He doesn’t get hurt. Can any of you please provide me some guidance to converting this game to multiplayer? Any links, tutorials and pictures will be appreciated. Please try to help me with the above stated problems.

Thanks.
Sohaib_Boi