Here's a few screenwriting thoughts from someone who has recently broken into the industry who didn't come from money, connections and lives in a different country far from LA.
It doesn't matter how many script you write in a year if you don't have incredibly solid samples. Going back, I would have written less overall scripts and focused on working and rewriting a few solid samples. Less is more! (if your less is super solid)
Spend more time developing the concept before hitting pages and run that idea past a few people. Spend time digger deeper, then deeper to ensure your concept feels fresh and has legs that can hold up against quite literal thousands of other scripts.
You don't need to spend $$$$$ on script consultants and doctors. Really. You don't. Get as many rounds of notes from peers as possible. Don't send a script up the ladder (to managers etc...) unless it's super solid. Coverage lasts forever.
Find your wolf pack. This has been the single most important thing I've done. I have my trusted people who I've grown to know and adore and love (all found on twitter btw) who will tell me when my stuff is shit. FIND THE PEOPLE WHO WILL TELL YOU YOUR STUFF IS SHIT
When you have a script that has been vetted by your people and you've given it a super solid spell check (I always pay for an editor pass) Then write 2 more. Having numerous solid samples will help you to stand out when seeking management.
Don't throw money at services/contests that don't have a GREAT track record. Listen to managers when they say they only trust (insert names) of certain services/ contests. It doesn't matter if you're a QF at some contest no one knows+ you could have spent that money on rent
It will take time. Like a hella lot of time. You will break into the industry like a dozen times before making money and even then nothing is certain. If you can do anything else, do it because you need god-like resilience
Last thing. Kinda only thing? Don't chase trends, political or social hot topics or what you think will sell coz that will be obvious on your page. Write from your soul and heart. Write the script you HAVE to write. Be okay that your voice and oddball experiences are on the page
Embrace your uniqueness. Anyone can format a script, but if you can make your reader FEEL -- they'll remember you and that will set you apart.
*ignore all the spelling mistakes. This is why I always pay for an editor pass ;)