Welcome! (1) There is an entire section devoted to understanding HP and writing good Hubs. I would encourage you to browse 10 or 15 How To Hubs. Some are more helpful than others and some will fit your style of writing.
(2) As you are browsing and learning, you should pretty quickly get a clear sense of what you want to do on HP (that will influence who you read and what you write). Do you want to write lots of informational hubs about products and services to make serious money, or write fiction, drama, poetry and to hell with all the stuff you have to learn and do in order to earn a "little" money, or you are here primarily to write, you are not terribly commercial, but you wouldn't mind receiving an occasional small (50-75$) check. :) I recommend choice three of course. :)
(3) Read, read, read, even skimming helps. (I don't recommend the Hub Hopper at all) You will see a pattern in what you like: Hubs you wish you had written, Hubs that sound like you, Hubs that address interests similar to yours. Now pick a handful of writers whose work you like, scores in the high 80's or 90's, and study their Hubs. What do they do? How do they organize their material? Lots of pictures and graphics or lots of advertisements? Are they a niche writer (handicrafts, political, religious) or do they write on many topics? Who do you want to be? Learn from them.
(4) Some people dive into the Forums, but that is far from the best writing on HP and often discussions deteriorate into angry and/or childish arguments. I think your time will be better spent elsewhere.
(5) Choosing people to follow. Obviously, you might want to follow people who write really well and on topics you appreciate. Beyond that, it is possible to develop friendships (of the literary and intellectual sort) on HP. People with over 600 followers will usually not have time to respond in depth to your hubs or your comments. I found the best writers and those with time to interact have between 200 and 600 followers.
(6) You could look at my Hubs (I am pretty good at commenting ). You will either think Wow! she is great, I like all of her stuff and I can learn a lot here. :) Or you will think, good heavens, this woman is crazy, a crummy writer, and I hate her subjects! :) Either way you will have leaned something about HP and yourself as a Hubber. :) Again, welcome to HP. There is something for everyone. :)