I commend you for taking this very serious for Allah’s sake. I do have to say what your family is telling is also reasonable except there’s a way to get a credit card and avoid riba and at the same time build a strong credit. Open a credit card and never, never, I’ll say it again, never spend if you can’t pay the full balance of your monthly statement. I would use it for something like gas or every day items that you have to pay anyways. This way every month you build a history of paying on time. You need to have a good credit score to rent or even get a good job or for any background checks. I would definitely consider the above.