I am new to Lego. I can't figure out the instructions as to where the gun and black hair piece go. It looks like they go in the Phantom somewhere, am I right or wrong? Do they snap in? Also, does the little robot guy just go in or snap in? Right now it's kind of rattling in there; I think it's wrong.
I'm assuming you are referring to LEGO set 70548.
I don't have this set, but checking the instructions online, I think this is what you want to know:
The black hair piece is optional. You can make your minifig wear the helmet or the hair piece, but not both at the same time.
The pilot fits inside the model, as can be seen on picture #31 of the first booklet. However, there is not enough space in there for him to carry his gun also. This is more often the case with Lego models - cockpits and cabins are not always big enough to contain both the minifigure and their accessories.
The droid does go in the model. In picture #7 of the second booklet, you put a round 2x2 tile in it, with one stud on top. It's a bit difficult to judge from the instructions, but it looks like the droid should snap on there.
In general, most things in Lego should snap into place easily. If it doesn't, don't force it - there is probably a Lego enthusiast near you who can help.