Can I order a new SIM card for my LG300 phone?

Can I order a new SIM card for my LG300 phone?

I'm trying to re-activate an LG300 which has not been used for approximately a year. (I was told at the store where I bought the phone that I would have to get a new SIM card, since the phone had been inactive for so long.) Where do I order one, or was the salesperson wrong in telling me this?