Not getting the job doesn’t mean you’re not good enough – it just means someone else was more suited to the role. And, when you think about how many people could've applied, the fact that you got an interview is something to be proud of alone.
Remember, you won’t get every job you apply for. And something better will be right around the corner. But, to prepare for that next interview, ask for feedback from the last one.
Ask things like, 'how could I have improved my interview?' – and take notes. Read them over later to decide what you want to take on board for the next one.