The idea behind using a credit card is to earn credit for when you actually need to borrow money. You should be using credit cards as proof you can pay back what you spend so you should have that money. An ideal use case is having the money on a debit card, opting to use a credit card and paying it off before it incurs a cost. Doing this would be free for you but could help greatly in the long term when you borrow for something like a mortgage.

But you shouldn't do this if you are already bad with money. I just use mine to pay for online subscriptions and have them automatically paid off because I know I can't be trusted to remember to pay them off

I (european) pay everything with a credit card (where possible, which is every store except some small independent ones). Then, I pay everything back by the due date. Why? In addition to a free loan while my assets are invested, I get 1-2% cashback. Yay, free money.

What we have of credit scores doesn't depend on our credit history as in the US though. Unless you currently have unpaid debt there should be nothing negative in your credit report. As it should be.

You're misunderstanding how credit cards are very often used.

Just because you pay with a credit card doesn't mean you are 'going into debt'. I pay my credit card off every month. I never accrue interest. But it's 1. Beneficial to my credit score to use it some and 2. I get cash back on some types of items, so it's just beneficial to use my card.