This is a grammatically correct sentence, but you would ONLY say it in the following type of situation:
Someone tells you that they want to get a new job. If you want to say that this isn't a problem for you, you might say 'I'm happy for you to get a new job'. It means that you don't mind if they get a new job in the future. You might say this to an employee or a family member.
Is this the situation you have in mind? Or has the person already got a new job, and you want to say that you are happy about this? If you want to congratulate someone on their new job, then this is NOT a correct or appropriate comment.
In this situation, you might say:
'I'm happy/pleased about your new job'
or
'I'm happy/pleased that you've got a new job.'
Right and wrong isn't only about grammar. It's also about context.