<prompt> Human: Some info about me:I am a 20 yo college student.I am currently searching for apartments with some roommates for next school year.I have about 12,000 in student loans.I make approx. 9K per year working on campus and over the summer.TL;DR Already dislike my Discover student card that I have had only 5 months, but I have a high credit score 720. Can Ishould I apply for a new card already or wait?Whats happened:I decided I needed to start building my credit November 2017 about 6 months ago. I realized there were a lot of benefits to responsibly using a credit card and that I wanted to have a solid credit score if possible by MayJune as I start apartment hunting with some roommates. I spoke with some friends and they had all recommended the Discover It card for Students. I was drawn in in part because there was no initial security deposit unlike many of the other intro debit cards along with some of their student rewards. I assumed I had no credit and I knew that I would be approved for the card. I applied and received the card in December about 5 months ago.Since receiving the card I have a spending limit of 500; however, I usually only have a credit utilization of about 20 whenever my statement posts per the recommendation of some family so that I have a balance being reported each month while never owing on interest because I always pay it before it is due the following month.The part that had thrown me off, is that the first month I had my card, my reported FICO score was already at 664. I did some digging and it seems as though my student loans were contributing to my credit score since I technically was never missing a payment on them, since I dont need to make any payments until I graduate from school. Since then, my score has gone up between 10 and 20 points each month and I am now sitting at 707 for this moth and expect to be around 720 when my statement is next pulled. All of this is really great!My complaints:In January I went online to purchase flight tickets to Mexico for later this year, and my Discover Card wasnt accepted. No big deal, I had the money ready on my debit card and I was new to the credit card thing, I was fine paying for it that way. However, I also realized, I was missing out on some major cash back opportunities. Then again this week I went to pay for some flights this time to Europe and again, they wouldnt take my discover card. More cashback I am missing out on. It also has occurred to me that in my upcoming trip to Mexico that I wont have the protection that a cc would offer trip is in early June. These major complaints along with the occasional place that wont accept my Discover Card in the States such as my SO and my favorite tea place has become more and more of an irritant as Id like to be able to use my cc and pay it off immediately rather than using my debit card.What Im asking:So all of this leads to, can Ishould I apply for a new credit card? I havent done much research into which cards Id be considering yet most likely some type of Visa or MasterCard though. However, Id like a card that has better rewards than what I currently receive through discover 2 gas and restaurants and 1 everywhere else and maybe something that benefits travel since I do tend to travel a great deal though it is less of a priority. Do I stand a fair chance on getting approved for another card? Is my credit historytime with a cc too short? Would it damage my credit score to apply to a card, since I will have to have at least a reasonably good score for any credit check for getting a rental property. Is it worthwhile to completely cancel my Discover card now as it is not my oldest account technically student loans? Should I get another, more permanent use card now, and cancel the Discover card later on? Maybe I am just being petty about the whole thing. I can live with my Discover card for the duration of my time in school if that is what is best.Also, if someone does happen to have some recommendation on a card I should apply for, I would gladly look into it.Thanks for taking the time to read.  <response>: Theres literally no benefit to closing the card except for an edge case youre nowhere near you have too much credit extended from a given issuer and want to apply for a card of theirs for the bonus. If you dont want to use it, stick it in a sock drawer and forget about it.My typical recommendation for people building credit is to wait a year and a day after the first card and get the Chase Freedom they wont approve people w less than a year history, but have a high approval rate after this for the nice bonus and potentially ongoing rotating categories if you dont continue to open cards.Barring that, you could look into whether you have a shot at Cap One quicksilver - nice abroad for the no FTF, has a bonus - but I think you likely need more history. Same for citi double cash for the 2 back, although I think the card is overrated - you get better returns c. 10-20 in bonus periods so I dont find a lot of long-term value in a card that earns 2 - once you have established credit, it makes sense to continue to open cards for the bonuses instead. 