Thanks for your thoughtful post!
You can’t go wrong looking to nature for guidance. It has served me well. As to the question of purpose, I have found there is a personal one based on our particular gifts. So we have great orators, musicians, engineers, nurturers and so son. People find meaning in those pursuits, a reason to live. However, these activities can end at any time due to forces beyond our control. Also, history is filled with people who succeeded in one area of life but otherwise struggled with addiction and personal tragedy.
There is another purpose which we share as humans. It is not dependent on individual gifts and cannot be taken away by forces we do not control. This purpose infuses all aspects of our lives, not just one area. Stay close to nature and it will be shown to you.
All the best!