I'm upset at my friend who is bailing on a weekend away with friends to go to his unexpected Job Orientation
Why would you be upset at your friend for committing to their job? It sounds like its important for them.
I'm upset because he lied to me about it and couldn't be honest with me.
Job duties must come first. Getting mad at your friend for cancelling his trip with you, when he has a job obligation, is not correct. Understand that it is his job and he has no control over the situation.
It's not his fault. I just wish he had told me about it.
I understand that you wish your friend would have just been honest. Maybe they felt ashamed and thought you would accept the lie over the truth. Work is important and you should forgive him for what sounds like a simple mistake.