how to make your 3d character you created in 3d max or maya into a first person control?

Usually the difference between 3rd and 1st person characters is only the camera strategy: the camera is simply childed to the 1st person character, while in a 3rd person it’s controlled by some script that keeps the camera at certain distance of the player. If you have a character model, just child it to your first person character - if you’re going to use the First Person Controller prefab, remove the Graphics child (just a capsule mesh) and child your model to the FPC.