sql

I'm attempting to create a query that would show the difference in date between a date recorded in a column and the current date, but I keep receiving the following error: "Cannot call method "getTime" of null." What function can I use to calculate this date difference in Google Cloud SQL...

So I'd like to learn programming by myself and work in the field later on but currently my knowledge and experience in programming is very close to zero. I'm 33 years old, not sure how much age matters at job applications. What would be the programming language or languages that I should study...