The only reason to contend for a winner's certificate from NaNoWriMo is to convince oneself that you can write consistently come rain or shine, inspiration or lack of inspiration and anything that family and friends can throw at you. It proves that you have a professional approach to your writing. If you want to succeed as a writer, the NaNoWriMo trial is a simple test of self-discipline.
HELP IS THERE
There are helpful techniques for completing the NaNoWriMo challenge. Their website has many hints from successful contestants. Support from family, friends and writing colleagues will aid your task. The Literotica Author's Hangout usually has a support thread started before NaNoWriMo to encourage authors to enter, and to cheer on those who start writing.
WORD COUNTS
The simplest aid is a word count, provided by NaNoWriMo. If you are writing a minimum of 1,667 words each day you are on target and will succeed IF nothing happens. If the In-laws descend for a weekend, or the cat gets sick, or any of the minor disasters that are part of daily living occur -- you will miss a day, and retrieving that missing 1,667 will be difficult. It is better to set a higher daily target, say 2,000 words a day. If you miss a day, the multiple of the extra 333 words will help get you back on course.
WHAT TO WRITE?
Despite the title of the contest, 50,000 words aren't the length of a novel. Writing 50,000 words in a month only proves that you can write 50,000 words in a month. It doesn't prove that you can write a novel. It proves that you have the application to write consistently. A novel might take you six months at the NaNoWriMo rate of 50,000 words a month and then there is the editing...
You could outline a novel in 50,000 words, producing a synopsis and several chapters. That might be enough to submit to an agent or publisher as a proposal, once you have tidied it up. So you could start on the way to becoming a published author through NaNoWriMo.
You could write down all those plot ideas that have been buzzing around in your head for months, including some scraps of each story. Beware that you don't run out of inspiration in the second week when NaNoWriMo fatigue sets in.