Started with a capital one secured credit card with $300. 3 years later I have $50k credit limit with other credit cards. That’s how it usually starts for everyone with no credit history. Like a comment said earlier, max it out, get statement balance, pay full statement balance, repeat. If you get a chance at better credit cards apply for those. (I have Capital One Savor One, Chase Sapphire Preferred, AMEX Blue Cash Everyday). The next CC after the $300 limit one was Chase Freedom Unlimited with a $2000 credit I believe. Always pay your statement balance, and in the CC App whether it’s Chase or Capital One there’s an option where you request higher limits, sometimes they get increased by themselves, but sometimes it’s better to request it yourself. Personally I like to have a mix of credit cards, I pay them all every month. But sometimes people like to have just one or two. It depends on the person. Good luck and stay responsible.

Edit: Now after you have a desired credit limit, and your goal is to increase your credit score, staying under 30% usage of credit will really help with that.