The forum for godot exists https://godotdevelopers.org/forum/
Commenting with "how do I do [insert basic stuff]" are kinda not fun to read in general ). It looks like you make fun of game developers (I suppose you are one).
Weapon model is exported from blender, animated with AnimationPlayer, a child of player's rigid body (camera as well). Script on player's rigid body switches the weapon animation.
Crystal have a script that checks if player touches it, then it does +1HP +1AMMO and deletes itself.