The best way I can think of would be to make an editor that saves the positions and then loads them into your game. However, if you're new this isn't something to attempt.
Here's an easier way
When I was new, I used to print the camera's X/Y/Z coordinates to the screen. I would then move the camera to where I wanted my object to be, write the coordinates down on some paper, and position the object there using POSITION OBJECT. It's a little sloppy but it at least gives you a pretty close ballpark range.
And keep following the tutorials, that's how to learn
.
EDIT: Your graph paper idea could work as well. If you made each square represent a certain number of units and took a certain square to be the origin (0,0,0), you could just count how many squares away from the origin your object was on the X/Z axes. For each axis, you would then multiply the number of squares by the number of units each square represents, and there you have your coordinates
.
