Nitpick: it wasn’t specifically because of the retrograde motions that they were called wanderers, but just because, unlike all the fixed stars, which don’t change their positions with respect to one another, the planets move against that background.
Messy Paint: you don’t say where you are located, but if you have a planetarium nearby, you might stop in some day and ask them to show you retrograde motion. Most planetarium staffers are happy to talk with the public about this kind of thing, and if they do a live star show, they can probably work it into the next one for you. He/she might even offer you a private show. When I gave planetarium shows, I would occasionally talk about and show retrograde motion.
BTW, we haven’t really discussed the actual appearances of planetary motion. So in case there’s no planetarium near you, let me talk about that for a minute.
If you go out tonight and look at the sky, you should be able to see Mars, bright and reddish in the southern sky a few hours after sunset. Over the course of a single night, it would be hard to observe it moving with respect to the stars nearby, but if you could take a snapshot of its position tonight, and again tomorrow, and the next day, you would see that it was moving slowly from west to east. If you had a star chart, you could plot that motion.
If you did, you’d find that the motion was not smooth and regular. It speeds up and slows down, and every so often it stops and goes in reverse (westward), perhaps tracing out a loop before moving forward (eastward) again.
As for the reason, we’ve discussed that: it’s because the motion of the earth, “passing on the inside,” is superimposed on the proper motion of the planet itself. If we could watch from the point of view of the sun, we’d see no retrogradation.
I hope this and the answers from the other posters have helped a little.