Incomplete ideas, thoughts and jottings
You have written a masterpiece and now you want to get it published. Firstly, think about why you want it published by someone else. If it is just to get it out into the world you can just put it on your website or social media. Typically you seek publication to home your craft and get the approval of editors and perspectives outside your social group.
Jo Bell's spreadsheet method is a very useful framework for submissions. I've followed it for the last few years and its really made a difference to my attitude of how I submit poems and stories.
Find magazines that fit you.
I have a number of submissions I aim for each year to make sure I'm getting work out there.
Be respectful of the editor's time. Follow the submissions guideline for each magazine and only submit when their window is open.
Be aware magazines get a lot of submissions and you may be rejected.