Maha Shivaratri Yama

I am new to learning and am attending a Maha Shivaratri celebration at my local mandir. On the schedule the list 1st, 2nd, 3rd, & 4th Yamas for 3.5 hours through the celebration. Under that, there are several other things happening. Can someone help me understand the Yama and then the different events under each one? Photo to share what I’m talking about.