You're just starting out, and your limit is tiny. It's pretty easy to get a $50,000 credit limit spread over several credit cards, at which point even $5,000 of spending per month is only 10% utilization.

With that being said, the reasons for using the card have nothing to do with credit score. They have to do with convenience, security, and earning cash back or other perks.

In the meantime, you can pay off your card every week to keep your utilization low, if you need to goose your score. But your score only matters if you're applying for more credit (e.g. getting a mortgage), so if that's not the case you don't need to worry about it and can let your score increase naturally.

Actually, it sounds like your score is already fine. Don't worry about it. 5-10 point changes are just normal fluctuations.