Collect data through a survey. Possible question is:
To what extent do you agree or disagree that in your community young people are able to meaningfully influence decision-making
For analysis a simpe percentage should be taken of the number of respondents in the youth age group reporting that they agree or strongly agree with the statement. Care should be taken in deciding whether this percentage applies to just those surveyed or whether it can be ascribed to the population as a whole. This will depend on the design of the survey and whether or not it was a representative sample of the population.