muscle question

_.B._ • 6.13.15 💍 - Mother of 5 🚼
Me and my husband just recently got a gym membership as we have been couch potatoes for the past 4 years and we were sick of it. 
Anyways my question is when going to the gym or working out in anyway for that matter, how many days are you supposed to "rest" when working a group of muscles? I have heated wait a day I have heard don't wait at all. Are we just supposed to keep working out even though we are sore? Will that hurt anything? Sorry if it's a stupid question but I genuinely don't know.