TBH learning all the technical stuff is great, but if you don't have a good eye in the first place then you're going to struggle to get great images. You have a good platform so learning the technical stuff is only going to enhance what you're doing already.
I think there's a bit of confusion with terminology as you say your kit lens doesn't focus far enough, but all lenses (at least all lens I'm aware of) focus to infinity, ie in theory you could focus on the furthest galaxy of you could see it
What you're referring to is reach (what consumer cameras tend to call zoom). You can get what are called superzoom lenses such as the Tamron 16-300mm which will cover most focal lengths that you should need, however with superzoom they are a jack of all trades and master of none. You should still be able to get some really good landscapes with them though. Generally people start out with two lenses, a short zoom (such as 18-55mm) and telephoto zoom (such as 70-300mm). These focal lengths cover most aspects of photography, and then as you get into it more and find out what you like to shoot you can then look into more specific/specialised lenses or more 'premium' lenses.
You've mentioned a couple of times that you've "rushed" your shots which is not the best approach to landscape photography tbh. Yes I'm sure we've all done it when you don't have the time, or with a partner that's getting bored etc etc, but if you can take time to consider the landscape, see how the light falls, consider the composition etc etc you will normally find that you get better results. Some people go back to the same location time after time waiting for that perfect light, or dramatic sky.