The way it works, is they usually only give someone a $500 limit, then double the limit every 6 months If you pay monthly.
Once you get a job you can get a bump to $2000 limit with the 1.5% back easy. You just need to get a job for that.
I'm 1.5 years out of college and have access to ~100k in credit cards with a score of 750. I started with a score of 540 1.5 years ago. It's really not hard at all.
I just have a lot of cards. If they want to give me bonuses for signing up I will take them. Free money.
Plus usually you can call and get the second year free too.
Regardless, I can cancel w.e. and the increase in my credit score is worth it. At the moment if I want to buy a house (for example) I get the best rates on loans
It increases your score because you have a lower credit utilization and you have more available to you (supposedly signaling how responsible you are).
My credit report (free from my bank) tells me my score is slightly lower than it would ordinarily be because of how short the card history is. I still get a couple "pre-approved" card offers every week and the occasional offer to raise a limit, but I just shred them.
At this point, I have enough credit from credit cards alone to buy a small house.
It doesn't matter how many times you swipe your card, you can get a card and never use it and and still counts for your credit history. The point being you have credit available to you but you aren't using it. You have four years of not running up your credit card, that's huge.
EDIT: Huh, apparently I've been ill-informed about credit history [1]. Guess I've been a dumbo and one of today's lucky 10,000.
[1]: https://www.reddit.com/r/personalfinance/comments/188xmi/is_...
FICO is based on your credit utilization (amount owed vs credit limit), history of repayment, mix of types of accounts (this has a minimal impact), number of new accounts, number of credit inquiries (aka hard pulls, this is also minimal), and length of credit history.
You had credit available to you for four years and you manage it very, very well.
Other scoring algorithms besides FICO may weigh different things differently but FICO is currently used in most lending decisions so it's what matters for now.
If you want to see your real Experian FICO 8 credit score for free you can do so at freecreditreport.com which is a site now owned by Experian. They break down each part of your credit score and grade you on each. (A-F)