Author Natalie Goldberg offers up some amazing advice in her tried and true book, "Writing Down The Bones: Freeing The Writer Within": Keep your hand moving, lose control, and don't think. It's great advice, if you can fight the urge to resist it, because it takes so much pressure off the creation process in the early stages of writing your novel.
If you liken your work in progress to a body, the core structure is the skeleton, or the bones. Everything is built upon that foundation. You add the muscles, the nerves, the flesh, etc. until you have an entire being. Therefore, if you work on first creating that skeleton and not worrying about anything beyond that, you will free yourself to create the basic template of your story. Admittedly, it's hard for me to write and not want to edit as I go. I want to feel that when I finish that first draft, that it will be all downhill from there. But truthfully, that's where the hard work begins.
Don't worry about the details. Write your story, even if it includes long rambling passages of description and dialogue. You will go back and change it later, but in the meantime, you are getting the words on the page. Don't let others read your novel at this stage, even though you may want direction and feedback, because it may veer you off course. You know you're going to make changes, you know it needs work, so it can be equally frustrating for a beta reader to give you feedback knowing that it's all likely to be changed up anyhow. This is the part where you write for YOU - no rules, just free-form writing,
When you have finished draft one of your ultimate epic masterpiece, read it out loud. Make notes in the margins. Does it need more action? Is there enough suspense? Are the characters three-dimensional? Is there a discernible plot? How is the pacing? Author Jessica Brody had a great suggestion - she uses color-coded note cards to write the information about what each character is doing throughout the story. After all, each character has their own arc and purpose. Are there way too many note cards of the same color? Does your story need more balance? Try and break the story down to its natural chapter breaks, making sure each one ends in a place that keeps the reader hungry to find out what happens in the next chapter. Once you have completed this first pass, you will have added your muscles. Stir and repeat and you'll have your nerves. NOW would be a great time to give it to some writer beta friends to see what they think.
Once you get legitimate feedback about what's working and what's not, you can know where to focus your revisions from there. When you have finished (if a novel can ever be truly finished) you will have the whole body, with all it's parts working in concert with each other.
Be careful not to rush any part of this process. It takes work, patience and perseverance. When you send your novel out, you want it to be the absolute best it can be. Further, as you've probably learned by now, the world of publishing takes a loooong time. I've read it articulated many places to remember it's not a race. If you attract interest from an agent but they want some changes, don't feel pressured to pull a week of all-nighters to turn it around to them. They want to see you put in the time to make it right too, and there are few things in life that come out perfect if we rush them. It just ups the ante for oversights and mistakes.