In my life, it's very constant that someone gets spooked at the idea of having a credit card. Building credit can be really useful for the future. You in fact need good behavior, specifically with credit to buy things like cars, houses, etc. The bank needs to see that you're trustworthy and deserve to have, say, a loan for the down payment of a property you're buying. If done correctly, you may not even have debt thanks to the credit card you're using.
Here's what I do: if I have cash, I keep the cash, always having the total amount present in my mind, and buy whatever I need with the credit card, but pay it in full, so long as it's within my means and doesn't go over the budget, AKA, the cash I have. It could be the smallest thing, like gum, groceries, movie tickets, etc. I pay in the moment with a credit card; again, always being conscious of the real amount I have in cash. When it's time to pay for the expenses made with the credit card, I get to use the cash. That's how, little by little, you may start to build credit.
Also, look into the benefits of using your credit card and the loyalty program it may have. In my case, I earn points if I use it and then I can exchange them for stuff. Sometimes the system allows for the points to double or triple depending on if there's an offer they're making, a contest, or simply by buying at stores that use these points, hence the brands behaving like allies to the point system. All this to say, study the way the points work in your favor. So far, I've been able to buy skincare products with them. In my case, the points expire over the course of a year, so that's a thing to look out for as well.
