You have the desire to do volunteer work, but why? Do you want to develop yourself? Do you want to escape the busy life in your home country? Do you want to learn from other cultures or just help "the poor"? Doing volunteer work with the wrong motivation can lead to a negative experience or a negative effect on the project. When your motivation is not clear:
We most certainly do not what to discourage you to do volunteer work. It is an amazing experience and will get you A long way, but it is very important to think about motivations to get the most out of your journey, not only for yourself, but also for the local community.