You’ve got your geometry welded together which will make moving the one to align with the other impossible.
First thing you need to do is learn about components and groups. You should go through the educational materials at learn.sketchup.com and the Square One videos on the SketchUp You Tube channel. Do that before you try to model the light saber handle and save yourself a lot of frustration.
Next, instead of modeling the parts away from each other and assembling them, model them in place so you can use the first part as a reference for modeling the next part.