This here writing thing is choppy water with ever-changing winds to screw with you. Any advice you get from writer's before you can be helpful, but ultimately not determinative. The map is always changing, and you've got to keep your head up if you want to keep grinding away at it.
Here's a few lessons that I've gleaned thus far that might be of help to you.
Fear Long Weekends
Most people in publishing are terribly overworked, especially if they're putting together anthologies or something else. Every time a long weekend comes along, you'll suddenly be bombarded by emails from anthologies and literary magazines as people spend the weekend catching up. Due to the law of large numbers, most of them are just going to be rejections. The normal situation of one or two rejections in a day is pretty easy to get used to, but the cavalcade that can be a long weekend is something that you might want to start preparing in advance for.
Editors Are All Over the Place
And that honestly is a good thing. Without that, we'd have a lot of the same stuff getting published everywhere. Just don't be surprised if you have some editors fawning over a piece of work while another really can't stand it. That is just going to happen. And it doesn't even mean that one is right and the other is wrong: they just have different tastes.
Manners are So Much More Important Than You Think
This one has been huge moving forward. Writing is a pretty small community and it isn't uncommon for writers to get into pretty public spats. Editors are often harried individuals just trying to make the world a better place, often through your very writing. That's a pretty noble profession and yelling at them because you disagree with them is a pretty bad call. The same thing if you get into a public fight with someone - sure you're going to have some people love you for it, but you're also going to have a lot of peopel roll their eyes if stuff descends into the gutter.
A great example is Ursula K Le Guin and Margaret Atwood disagreeing on the definitions of science fiction and speculative fiction. Despite there being a disagreement, both did the amazing job of keeping it civil and respectful. The moment that you start calling another writer names or decrying their work publicly, you're asking for your fans to roll their eyes at you and move on.
Luck is Surprisingly Important
This should definitely be taken in the context of luck being what you make it. If you never submit a short story, never write ablog post, etc, then you'll never be lucky. So much of writing seems to be being out there and hustling every day until you reach those moments of luck. One of my first publications was because an editor had a writer pull out last minute, and asked me to fill in. From that relationship I leveraged it into more publications and more work with both him and then others.