Need help to determine statistical method

Dear Friends,

I'm going to test that significant difference of social security measures among Pensioner, epf beneficiaries and non beneficiaries. I'm going to conduct through survey in three samples represent above population categories. I'm going to collect data from around country using Sri Lanka department of Pensions network.

Pls assist me to identify method to check statistical difference in three samples. And how to evaluate findings from this research.