How can I help to participate in data collection or research work as a field researcher?
The first step before starting a PhD would be to find a potential supervisor who has some expertise in the research domain (not necessarily the specific topic). First there will be some discussion with this supervisor about the exact research topic and the motivations for the research: a PhD student's expertise in a particular topic is not enough to justify research on this topic, there must be some scientific reasons why this topic is a relevant research area.

Then you will see with your supervisor about the best method(s) to achieve these research goals. Imho it's unlikely that a supervisor would agree with a method which involves you as a subject, but I'm not at all in this kind of domain. In any case your expertise would certainly be useful in contacting subjects and targeting the right research questions.