As you select your targeting during campaign creation, the default "location" field you will see is Countries. In order to target people more accurately (cities, states/regions), you can click on "Show location options" to expand the other fields.
It should be noted that Facebook only accepts the lowest-level location option. Trying to target people in Texas AND people in the United States will result in an error. If you want to target people on the state/region and/or city level, only select the options on that level.