If you're serious about this writing thingy, you'll want to save yourself time and be aware of any writing issues before they even arise. Here are three things that you'll need to know about before you get too many pages into your book.
A common bugbear of mine involves joining two actions together using the words 'as' and 'while'. People who do it, do it a lot, and after a while, it gets boring.
There are lots of ordinary words that we have to repeat as we write. They're building blocks, if you like, creating vehicles that carry along the more interesting words and phrases.
But repeating unique words, phrases or descriptions several times in a paragraph, or a page, or even a chapter, makes your writing seem stale.
POV is the way editors and experienced writers refer to 'Point of View', which is simply this: the viewpoint through which your story is told.
The most important thing I can say at this point, is that whatever Point of View you choose, you need to be consistent.
At a few different points in your novel, you'll need to reveal information that is important for the plot to work. It might be back story about a character. It might be technical information about a piece of machinery which is important to know. It might be a detail about the way your fantasy world works.
Whatever it is, you're gonna have to dump some info on your reader. And just like in the real world, dumping needs to be done right.