That’s the landscape, but the landscape is pretty tough. Icon an non starter. Vertigo very tough without having some evidence of self published stuff. To write for the big two you need to give them confidence they can work with you, which means showing previous work produced on time at a high quality with fresh ideas and new perspectives. It’s like applying for a job that requires at least 5 years experience.
First write. Write three things of your own. Keep at it till they’re good, then ask others for input. Think and refine continually. This gives you three books you can talk about at any time. Then write a couple of scripts for the big 2 as if they called you up. You can aim for a big character, but develop your skills better on smaller guys. Look at what some of the greats did with their early books - Hickman and Johns and Aaron and BKV and Kirkman and so on. Get good at seeing characters in a new light. Doesn’t matter that these scripts won’t be optioned, consider it going to the gym for comics.
Of the three self created stories pick the best and write the best issues you can. Share with others and get feedback. Make it great, make it something that will have others paying attention. Don’t make it a gimmick, or a slight variation on a typical comic convention (like a superhero who’s also a serial killer or something). Look at some of the best first issues to come out in the last few years, particularly the mini series that have done well. Study Millar with Huck and Chrononauts and Starlight and Superior and Empress. Look at We 3 or Saga. What did they do, how did they structure things, what was put into that first issue?
Then you’re ready. 2000AD is a lottery, and not the jumping on point it was 20 years ago. There’s lots of small press publishers out there who can get you connected or publish you. But it’s all going to be for no profit. Your best bet is the Image path, and with that great script you find a great artist and go for it. If you self publish get ready to work conventions and sell every copy 1 at a time. But that can get you noticed, simply by being part of the self publishing community.
If you feel discouraged don’t. Lots and lots and lots of people have picked this path and made it work for them. It’s an industry that’s welcoming to new talent. It’s worth looking at some of the folks who have done well, whether thru convention sales, kickstarter or comixology. Every path is different, that’s the main thing, but you can get there so long as you focus in the right direction.