First of all - welcome!
As far as the party goes, my DH and I are boomers too and we went to the party last year. Some people dress up, some do not, but it's still a lot of fun. They have dance parties going on, lots of characters, free candy and beads, and virtually no lines on most of the rides. The fireworks are totally amazing, and the parade is fun too. You'll love it! Arrgh!