How does one determine where they want to go to vacation?

I've always daydreamed about vacationing, nowhere specific because I never thought it'd be possible. I've never been anywhere and neither has my immediate family.
Now I can finally afford to, have accumulated some time off work and I don't even know where the hell to go.
I'm in Texas. I'd like to go North I suppose. Different scenery, better weather..
I don't know what's good to see. Things I've done in life so far have always been a let down.