Got fired

My store got bought out by a huge franchising chain and ever since then it’s started to go downhill. All the new people that trained us were kinda unprofessional some even showing up high and reeking of weed, smoking cigarettes in the parking lot in uniform in front of customers and telling us differing things on what to do. Seeing as my store had a lot of minors me and 3 others were fired for not aligning with the store’s performance goals. This one shift lead at my store has assaulted another employee biting them and clawing at the neck the district manager was notified however she received no punishment. Is there anyway I can report this to corporate (we also have had multiple huge health code violations with mice that were overlooked and swept under the rug by management) We were encouraged to not say anything about this because if the store gets shutdown people can’t support there families but it’s a huge issue to public safety. I’ve worked here for almost a year and a half now was really sad really loved the job.