>>What are some things that the best kinds of writing you come across have in common?
They tell a great story. While there are many elements to writing well, and many books on how to do that (some of which you should consider buying and reading), I'd say a great story is the most important. Right from the book blurb to the very first sentence. Grab your reader and don't let go. Readers will forgive a few imperfections in someone's writing if they get that one element right. Also, since you're just starting out, approach the work with the expectation that you will have to do multiple (many?) drafts, especially that first sentence, paragraph, page, and chapter. But don't get paralyzed trying to perfect them before moving on. The very act of writing the novel will almost certainly alter what you want to say at the beginning.
On a site like this, where you can get widely varying feedback from different authors (including quite a few who are published), you'll quickly learn many of the elements that go into writing well. But it's not just their feedback that's very important. So is reading and studying their writing, so you can decide which elements of each author's writing or storytelling style you like and may want to emulate versus those you don't. Do the same with novels you've read that you enjoyed, but this time, approach them from what the author can teach you. For the stories I write, I particularly like Frank Herbert's Dune novels, as well as Dan Brown's Angels & Demons. I've reread both many times.
The points system on this site, while not as onerous (anymore) as other workshop sites, still requires you to read and critique other members' stories. Approach those from the perspective of what their writing can teach you; collecting the points to post is of secondary importance to exposing yourself to many different writing and storytelling styles.
This is where a lot of would-be authors give up. They realize that writing that first successful novel is a lot of work beyond just writing. Anybody can write, but most people don't do it particularly well at the beginning. There are authors here who will tell you they thought their first written work was great until they joined this site and realized how much there was to learn. Some of those same authors are now published and among the most skilled on this site. I have an IT background that has always included technical writing, and I can tell you, my first attempt at a novel, which I thought was pretty good at the outset, I now realize was total crap. Taser-stunningly bad. :-)
You'll probably get a lot more feedback to this post as it's a great topic. Be sure to look at the forum article entitled "How to Get the Most Reviews of Your Writing" (pinned at the top of this forum), which should help you maximize how much feedback you get during your trial and help you decide if this approach to writing and learning to write suits you. I've been here 12 years, others even longer, and for us this approach to writing and learning is ideal. It's also how most online critique sites work. The most important aspect to getting lots of reviews is to give lots reviews. Be sure to keep your posted chapters to a reasonable size (see the above article for suggested length/wordcount) to help the most number of readers here find the time to review your story during your trial period.
Is your currently posted work, Life Extension Program, the lgbtq+ psychological drama you were referring to? I'm a bit swamped this coming week, but I'll do my best to get to it. FYI, one of my two novels currently in progress, Archangel Syndrome, is sci-fi with a number of gay characters living on a conservative Christian world. It's a great way to explore the issues arising from that, including the evolution in the thinking of the planet's sixteen-year-old crown prince, Joseph, one of the story's two main characters, who has a lot of evolving to do, especially since he himself may be gay and is horrified by the possibility. :-)
Welcome to the site.
Dirk