CUSTOM CSS IN TEST ENVIRONMENT

Good Day… We have an existing website but we want to modify the design based on our personal preferences. I know how to code(HTML,CSS,JavaScript,Bootstrap) but we do not want to do editing in production of course… How can I test my designs before deploying in the production? Hopefully someone can teach me step by step. Thank you

It is possible to make a test copy of your live store, as long as you keep the storefront of the test copy closed. An article in our docs should explain more.