Should I get a credit card? If so, which?

Hi guys. I've heard people say that you should start having a credit card at some point to build good credit.

From what I've read in the sidebar, I'm a good candidate for it: I'm 27 and have a steady job, and ~40k in the bank. I have 5-10k in student loans from undergrad, but because I'm in grad school, the loans have been deferred without interest. I'll have a STEM PhD in a year or two. I'm single, don't own a house or car. So, is there any reason I shouldn't get a credit card?

I've actually never checked my credit score, but I've never had any outstanding debts or anything. I guess my main question (assuming the answer to the above is "get one") is, how do I tell which card I should get? What should I look for, how can I tell one is good?

I have a checking/savings account with Citibank. Would it be better or worse for any reason to get a card with them? It intuitively seems like it would be simpler. Here's a list of credit cards I could get from Citibank.