Hi. Welcome to the world of knitting and Knitting Help! You're starting with a circular needle, that's great. You can use it to knit back and forth for flat and then you can use it to knit in the round and make tubes which are very useful for many things. Bamboo would be good to start with, people who teach have said it helps you get off to a good start. I think the 60" might be longer than you want for a first needle. Are you buying at a local store or on line? The options you have available might be different depending on where you're buying. Oh, yes, we always want more info so we can help you the best we're able.
I should never overestimate my basic arithmetic skills.