> all the planets also rotate on their own axes in a counter-clockwise direction
Actually, Venus is also an exception. It does not rotate the same way as Earth, Mars, etc. (The sun rises in the west there and sets in the east.) It also has an extremely long rotation period -- longer than the Venusian year.
Also check out Kerbal Space Program. I had my intro to prograde, retrograde, normal and antinormal orbital mechanics 101 from that. Not accurate, but it ingrains an idea.
KSP is such a great game. Best $40 I've spent on a game in a long, long time.
I've gained quite the appreciation for the initial pioneers who attempted e.g. docking maneuvers with the spacecraft of the time. Definitely a steep learning curve in-game, but once you get the basics of how to get to orbit it's pretty easy to wrap your head around transferring to other orbital bodies.
I can highly recommend figuring out the various keybinds (some are not so obvious, e.g. space for staging) and then just messing around a while. Soon enough you'll run into not knowing how to do stuff like a hohmann transfer soon enough at which point you can start googling.
I think it is because the article has sentences which uses 'right to left' & 'west to east' in series. This video[1], demonstrates prograde & retrograde in the same perspective as the one written in the article; watching the video and then reading the article should help.
I think the problem is that the article says to imagine looking "down" on the solar system from "above" the sun's north pole. So the counterclockwise movement of Earth means it is passing another planet from right to left, so the view of the planet is left to right, from this perspective.
But that's not really how we think of Earth. We orient "up" as "towards the north", not "away". So the whole thing is backwards. It's easier to work out if you imagine viewing from the south pole, watching the planets orbiting clockwise. Then Earth is passing a planet like Mars from left to right, meaning the view is changing right to left, which is more obviously East to West.
Actually, Venus is also an exception. It does not rotate the same way as Earth, Mars, etc. (The sun rises in the west there and sets in the east.) It also has an extremely long rotation period -- longer than the Venusian year.