I'm a 92 y.o. fairly fit male , can these exercises benefit me & will I be able to do them?

Hello there William !
Nice to meet you here!
Have you tried Day 1? Are the movements or poses too difficult?
Most poses can be modified or changed to suit the person practicing, it's very difficult for me to give an answer here, too many variables and things to consider. What I can say is to feel free to do this challenge to the best of your abilities making your own modifications and changes as it suits your body and needs. Not necessary to do anything if it doesn't feel right for you. I really hope this is somehwy helpful and I'm here to help more if needed!
Best, Robert

Okay, I am back to try again. Day #1

Welcome back Cassandra!! Did you do the entire challenge before? By saying you'll 'try again', does that mean you had difficulty and stopped? Let me know how I can help and keep me posted as you move through the days, I'm here for you!