So basically what should i consider if i want to remove collision between players? (How can i make players able to walk through other players)
You can use thePhysicsService and the CollisionGroups. Put all characters into the same CollisionGroup and set Interaction with eachother to false.
Find the player's character model. Then, find all of the parts (Legs, arms, head, and torso) then make them can colide false.