Can I take my cellular ipad and buy a sim card for it to have data?
Yes, you can. Though it's probably more efficient to get the sim for your phone and tether the iPad, if you need it. (I travel with my iPad, but don't usually carry it around with me.)
Thank you. I use google maps a lot and they are so small on my phone I thought a mini ipad would be easier to read. But a ‘phone sim cards’ will work like a phone SIM card, right?