@Jacob Rowland, hi and welcome to BP!
First, congratulations on thinking about investing in real estate at such a young age. I too started thinking about it my junior year of college. It took some time, but I got started eventually.
I want to encourage you to do one thing first: make sure you graduate. There is time to think about investing once you're out and moving in the market. My guess is you're going to college to study something that you'd like to do. If not, then this might not make much sense, but get that degree nailed down and more importantly find ways to apply the knowledge that you are learning. The old "sheep skin" isn't worth what it used to be, but the knowledge absolutely is. Be sure you are taking courses that are rigorous in math, statistical analysis, business, finance, etc. Avoid the "soft" disciplines that have little market reward.
My advice: stay away from credit cards. They're more hassle than they are worth, and you're tempted to overspend for a variety of reasons. Only a small percentage of people play with those snakes and actually come out ahead. The odds are stacked against you from the start. And as you will see in just a minute, they are totally unnecessary risks.
Yes, get high marks for paying rent on time. That's an excellent way to build references, which are important for developing relationships with private lenders/money partners.
What you will find in the world of REI is that a credit score only gets you so far. After 4 FHA loans, you're done. The Govt won't give you any more super sweet terms. The good news is you don't need (and probably don't want) those "super sweet" terms. FHA and other Govt-backed loans have a trade off for those sweet term: hefty fees and lots of hoops to jump thru.
Private money is better. It allows for unlimited creativity. And perhaps the best part, it is DEAL based, not credit based.
I know too many folks who worked to get a good credit score, then bought a sub-par deal because some mortgage broker who couldn't care less if they paid gave them a huge loan based on their credit score, then they sold that loan on the secondary market, removing the lender's risk. Years later the borrower is still sitting in that sub-par deal making no one rich but the loan servicing company. In short, the lender has no reason to hope for or encourage your success. Their goal is to loan you the most about of money possible, make a commission based on that amount, then dump your loan onto someone elses' balance sheets and go do it again. You succeed: they get paid. You fail: they get paid. Literally zero incentive for them to help you make good decisions.
Private lenders will tell you when deals are bad by refusing to loan against them. They are a wealth of knowledge and industry experience. If they won't fund a deal, it's not because you lack a credit score. It is because the deal stinks, and you should avoid stinky deals, right?
So, think of it like this: do you want to get a high credit score that allow you to borrow money huge amounts of money to purchase sub-par deals that disappoint you and leave you wondering why you never achieved much success, or do you want to leverage not only the funds but also the wisdom and experience of private money who tie their success 100% to your success, and who can act as mentors and coaches so that both of you get paid for your efforts?
I hope this helps.
