Thanks for the Respnses

The people in CO are super friendly compared to CA. We're laid back, not uptight about jobs in the tech industry and enjoy working to play.

As nice as it is here you'll have no problems meeting new friends just taking walks around your new neighborhood. There are tons of classes for the little ones and I've met a lot of lasting friends through the classes, and of course storyime at the library.

Which part of CO are you moving to?

I think a block party right after a move could be overwhelming for a little one. If you have an opportunity to meet and make a connection with a few neighbors before Halloween, maybe you could arrange a play date with 1 or 2 kids his age and their parent(s) to admire each others' costumes or to share a treat.

S., I have moved from Oklajoma to Ca, from Ca to Guam etc many times over the years. One word of advice... Don't add anymore stress on your child or self than you will already have. Making a move within the dame town is hard enough with a 2 yo without learning an entirely new way of things. Let him not be over whelmed by to many new things at once. Most 2 yo don't do well with many people all at once anyway.
I guess I have to many law enforcement officers in the family but they cringed at the thought of sending flyers to strangers when you have not had a time to get to be comfortable with the area. Start with a church setting and maybe contact the Chamber oc Commerance of the town and see what might already be planned, or with a neighbor you might meet or a landlord. Believe me your little one would be happy with a bag of cookies and 3 pieces of cany you gave him when all the boxes that are still not opened are facing him.
But I do admit to being one of those moms that actually bought candy and doingit all at home vs letting them go out to strangers .
Good Luck with the adventure of moving and I hope it works well for you to get him signed up for some class right away.

Some people freak out about Halloween parties, so it might not be the first impression you want to make. Maybe just a yardsale right after you move in would help you to meet all of the new neighbors, we do usually have things to get rid of when we move.
Other than that, just do some walks and introduce yourselves to everyone.
A party would be kind of daunting right at the beginning since no one knows you. I dont think I would go to a party if new people just moved in. Your son will probably adjust better than you will.... I wouldnt worry about it too much.

it's not a silly idea. you know your son best. mine at 2 would have appreciated just a calm loving mom and dad to reassure him during this stressful time. kids are all about routine, so to me the more in his "routine" you can keep him, the happier he'll be.