No it's not necessary. All they need is chick feed and water, and a brooder with some warmth, which I'm sure you've already taken care of.
You can do a search and read the pros and cons of vinegar -- it is generally felt it needs to be organic apple cider vinegar (ACV) and you only use a little. There are a bunch of other things some people do, a little sugar in the water the first day, supplements, etc., etc., but none of it is necessary.
Take a deep breath, check your brooder temp before the chicks arrive, be sure they have a cooler spot to escape to -- and enjoy!