How to setup environments for Cypress.io

I am taking a swing at setting up a test suite for my company's web app. We use four environments at the time (Production, Regression, Staging, Development). I have environment variables setup in my cypress.json file but I would like to be able to switch my environment for example from regression to development and force cypress to change the baseURL to my new environment as well as point to a different cypress.json file that has development variables. The documentation around environments on cypress.io is a little confusing to me and I'm not sure where to start.