I've urged writers to sign up for free newsletters to keep up to date on current trends and markets. Here is a short list for you to consider. Go to the website and, if it appeals to you, sign up for the newsletter. You can always unsubscribe at any time.
1. Writing Career
2. Writing World
3. Children's Writer ENews
4. Practicing Writing
I'm only listing four. Better to start small and add others if you think you have time for them. Reading too many newsletters is one of the traps writers fall into. I wrote an article some time ago about the traps writes can fall into. Too many newsletters is only one of them. Read the article here.
There is no rule that says you must read every word of every newsletter. When it arrives in your inbox, scan through the whole thing and mentally mark the articles/call for submissions or whatever that you;d like to go back and read.