Basically, everything in space is a moving target.

If you'd really like to nail home an almost intuitive understanding of orbital mechanics, I recommend Kerbal Space Program. Imagine Minecraft NASA. You plan, build, launch, and fly space missions using a simplified physics model. It's insanely fun and addictive, as long as you can get past the frustrations of early failures.

I cannot recommend this game enough. I've got hundreds of hours in, and I'm at the point where I've got huge spreadsheets carefully planning out mission parameters to spec the requirements for my new heavy launch platform to colonize the solar system. I'm even assembling a long-term research station in orbit that will eventually be parked around a gas giant.