Anytime you want! The wedding isn't until Monday evening at 5pm on Labor Day (Sept 2nd).
No. Your presence attending the wedding is enough. If you choose to give a gift, we did set up a cash fund for a honeymoon.
There are several great options around Colorado Springs. I did make a list of places under the "travel" tab. If you're traveling with a few people, I would highly suggest renting a house/condo/apartment on "VRBO" or "Home Away" as it could be more cost efficient.