Usually Amazon sells SIM-FREE (or Carrier Variant) phones, so plug in a SIM card for any network.
If it was locked to a network; Amazon should have informed this but you'll have to get a SIM from the stated carrier.
As for the touch issue, MS are rolling out the update, doesn't matter what carrier as it's an OS update, not a firmware update (which would have required carrier testing & approval). Try going to Settings >> phone update >> check for updates, if not available yet, keep trying you'll get it soon enough...
G.