Data plays a huge role for the analysis. It is used in various field for various purposes. There would be nothing without the data. It is the data that helps to increase our performance and production in every field.
It completely depends on your team to choose the data, you can make manual survey and collect the data or else you can download over the internet perform sampling and proceed with the calculations, or you can choose certain tools that generates the data it depends on your team and team members. There certain tools that provides you the data. Have a discussion with your team and choose with coordination. The data is rabdomly selected using sampling techniques and the random sample is used for further analysis.
You can choose any of the data that you are interested in may be a data collection of shoe size, nail growth, age, weight etc.