Kalu Yala was the best summer of my life. I learned more in that summer than in most of my college career. The focus is to build a community. Each student/intern focuses on one individual (or group) project and a program project. You have free reign to focus on what interests you.
This isn't to say the program was easy or sunshine and rainbows (Panama rains a lot). Building a community is hard messy. But Kalu Yala can be the best experience of your life if you will let it. Use it as an opportunity to practice not having expectations, for living in the moment, for appreciating the big and the small for exactly what they are. Do not do this program if you want to be comfortable. If you expect to be comfortable, or to have an easy semester, you will not make it.
If you are open to an experience and willing to take it for exactly what it is (it will be different to everyone) then apply for Kalu Yala. You owe it to yourself to take the chance and see if you can let go of worry and expectations and simply live your best life.