Boss closes company without giving notice, giving notice or paying salary?

Hello, I'm 18 and have had a part-time job at a restaurant for almost two years. I was just on vacation for two weeks when a friend suddenly messaged me and asked me why our restaurant was closing. I didn't know anything about it, but then I saw on Google that it was marked as permanently closed and that a post had been uploaded to Instagram confirming the closure.

I knew nothing about this and have called and texted my boss several times over the course of more than a week without any response. We communicate via WhatsApp, so I know the messages are getting through.
I have not received any notice of termination (although both sides require one month's notice), I have not been informed, and I have not yet received my salary for the last two months.

I don't know how to proceed now, as I depend on the money and would therefore be looking for a new part-time job. However, I can't do that without being fired first, and I also believe that I have the right to know personally if the company I work for simply closes down.

How should I proceed now? What options do I have?
I actually have a very good relationship with my boss, which I would hate to ruin now.