Arborist - yes, but expect to get absolutely flogged for the first few years. You’ll not need to do any sort of fitness/health stuff in your own time, work will take care of that. Learn to climb early, get in school early so you can be ready for the next step when your body gives out. Learn about ecology, learn about climate change. Learn about tree risk assessments, get a good spiel for convincing people that tree risk is incredibly low. Plant trees.