How do i properly change characters

Hey guys,i want to create an online multiplayer FPS game and followed a tutorial on youtube. (Virtus)
Finally everything works! (yay)

I dont like the tutorial Character so i got new models on Mixamo.

My attempt was to duplicate the FPSCharacter and add a different mesh + animation blueprint manually.
Which did not work at all. All functions like HP,shooting and Ammo counter dont work anymore.

So i guess im doing that wrong already.
And i still dont know how to setup a menu where you can choose different characters.

  1. How do i get multiple working characters
  2. How do i make a character selection screen?

I really hope anyone can help me.