Welcome! Something that really helped me write articles was this page: https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet
My advice would be to try and include at least one image, break your article up into sections with headers, and read your post over a thousand times before you submit it. Yes, you can edit, but it's best if you keep editing to a minimum. Also, try not to write about topics that are popular. Steem needs more diversity!