As a reasonably successful pro author with a ten-year career, here's the best advice I can give you today.
Don't listen to me.
There's a thing I called Established Author Syndrome. Basically, it goes like this. "When I was breaking in, we ..., therefore you should ..., because that worked for me."
I heard it when I was new. An experienced Big Name Author got up at a convention and told the aspiring writers in the audience to never publish in the small press because it would kill their careers permanently. This was said in front of me in 2004 at Norwescon, the day after the Hugo ballot had been announced with my name on it for Best Novella (which I did not win) and the Campbell Award (which I won that year). And me with exactly one pro appearance in print at the time, in SFWA terms, and some dozens of small press appearances. I was offended, frankly, because the advice was so stupid, given that exhibit A (me) was sitting two chairs down on the same panel as the BNA giving it.
It didn't take me long to figure out that what the BNA really meant was that given the state of the small press when he emerged, it would have killed his career then. Of course, he had over two dozen pro periodicals to sell to, instead of three digests and Realms of Fantasy. The Internet wasn't even a gleam in DARPA's eye back then, let alone online markets. "Small press" meant "subsidy publishing" in that era.
But he didn't qualify his advice, and most of the people hearing it didn't have the frame of reference to qualify it on their own.
This a function of human nature, not bad behavior or deliberate misinformation. We all believe our experience is central, core, valid. But it's also a truism that genre publishing goes through transformations every five or ten years, like a snake shedding its skin. How I broke in ten years ago was a bit unusual even for the time. It's frankly irrelevant today.
So the next time you're tempted to take my advice about publishing, markets, breaking in, or really, anything, consider this. I know what I'm talking about, for my experience. And my experience hopefully has value for you. But it doesn't mean I know what I'm talking about for you. Because I'm not breaking in today's market. You are. I've got Established Author Syndrome. You don't. (Yet.)
In other words, don't listen to a damned thing I say. Including this advice right here.