You know what magnets are, right? Yeah, they are an object that have two different magnetic poles, the north (N), and the south (S). if the same poles (e.g., S and S) meet they will repel each other, but, if different poles (e.g., N and S) meet they will pull each other.
So then, what is an electromagnet? An electromagnet is made by wrapping a nail, or a bolt with copper wire, and putting the ends of the wire on a battery. So, it works because, the wire passes an electric current from the battery to the nail, so the nail becomes magnetized. And it will have more chances to work if you have more coils, and less space between them.
I have made an electromagnet before, and of course, I have had my difficulties. For instance, when I first made it, I had a few number of coils, and had a big space between them. Then I tried a smaller wire, but it was too short, then my dad helped me coil the nail, he made the coils had less space, and a larger number of them. Then the electromagnet worked! Sure, it did only pick up small objects, but it was magnetic, so, it was a win!
So, to me the moral is to never give up, because, everything will work out in the end.