First, write the story and then research. Don’t get bogged down in unnecessary description. Facts for fact's sake bore readers. All that is needed is the discreet inclusion of a few authentic facts. There is no need to be an expert. Find out information that is relevant to the plot already planned.
Use research to illuminate characters and to advance the plot, otherwise leave it out.
If you never complete a first draft then you never know your story. You must write to the end.
Write without full knowledge of what you are about to write. Let the subconscious sum up the premises and intentions you have slept on and thought about over many days.
Write without judgement and do not edit until the last word of the first draft is written. Only then do you rewrite, rewrite, rewrite.