I am brewing my first batch it is an American Amber kit. Its been fermenting for about a day and the airlock blew off. Is it ruined or is there anything i could or should do?
It's most certainly not ruined. I'm assuming it's still fermenting hard so it's creating a lot of CO2 that will push out of the opening at keep outside air at bay.
What you should do (especially if you don't leave much headspace) is make a blowoff tube.
Yeah, use a blow-off tube to prevent in the future. Also, use a primary vessel larger than what you're using. i.e. I use a 6.5 gallon carboy for a 5 gal brew which allows plenty of room for the yeast to do its thing. It is typically a good sign that your yeast is doing its job. However clean with sanitizer asap to avoid infection and replace with sanitized airlock. Peeps here have had beer all over their ceiling due to aggressive fermentation. RDWHAHB