Agile is NOT new. Agile is how we have learned to do things since the beginning of time. How we challenged and learned about ourselves since we were born.
WATERFALL is actually the new kid on the block! And it doesn’t work. Not without significantly more work and risk.
Would you decide today what you are going to do on every single day of the rest of your life? You wouldn’t do that for the rest of this year. At best you’ll do that for next week. And only with a pencil in hand!
So pick a direction and start making stuff. You’ll figure it out along the way.