Penal Code section 496 is a "wobbler", meaning it can be charged as either a felony or a misdemeanor. If the police have an option to arrest and book you on a felony, they will, since the number of felony arrests the generate factor into budgets, etc.
Will you be charged with a felony? With no record, it's unlikely. Will you be charged at all? That depends. It's up to the DA to review all the relevant reports and decide if they believe your "I didn't know" story vs. they think you knew and just lied to the police.
Either way, you'll need a good criminal defense attorney in your corner to protect you. Start your search NOW. They can try to make sure any video surveillance footage is preserved if it could exonerate you.
496 pc requires that at the time of the incident you knew or reasonably should have known that the items were stolen. This does not appear to be the case hear. Thus, they would have a very difficult time proving their case.
It certainly sounds that at the very least, you have a winable case. The DA is the entity that decides what you get charged with, if at all. It is imperative that you have a lawyer ready to represent you ASAP. Often times an attorney can talk to the issuing DA prior to charges being filed. This can sometimes prevent charges altogether or perhaps have them filed as a misdemeanor instead of a felony. However, in the event felony charges are filed, you certainly need to have a lawyer fighting for you and assuring that you are not going to be convicted for something that you should not be. This is a crime that requires very specific elements be met in order to be guilty. You should sit down with your lawyer and develop a strategy for defense immediately.