my first mash. Combined all the ingredients in a "recipe" I followed. Added the yeast and it started working rather quickly. My airlock is due to come in the mail in 2 days. So I did the whole balloon/condom topper until it arrives. But after I put it on top and poked the small holes for the gas release the balloon still filled with foam and thankfully I was still awake. I removed the balloon and cleaned it well. Put a new one on same thing. My yeast is going crazy. Did I do something wrong? The foam wants to overflow.
Sounds like a normal healthy fermentation. You did nothing wrong. In the future you could get a piece of sanitized tubing larger enough to fit in the opening of the carboy and jam it in there. Then direct all that foam into a pitcher or bucket of water at the side of the carboy. That's called a blow off.
But what you did was fine. Once the foaming slows down it will still be fermenting. That will be a good time to put the airlock on. Not before or you'll be cleaning the airlock of foam too.
In addition to the answer brewchez provided, here is something I have done in these situations: Get a 3-piece airlock and some 1/2" tubing and fashion it like so:
I fill the bucket with bleach or star san.