Well, some notes.
Amarillo sits on an open flat featureless grassy plain for a hundred miles east and west, but gets all mountainy desert north and south. This means it's a permawind corridor. A good 10-20mph wind that just never lets up ever. Dust is a problem, along with fast moving and rapidly changing weather patterns.
The people in 'the panhandle' area actually fit the stereotype of Texans much more than almost any other place in Texas (which is actually a quite cosmopolitan and diverse state). Not a lot of black people in Amarillo, but lots of Mexicans, fluent in English and not. The rest are portly and uneducated white folks. Amarillo dominated the global teen pregnancy birthrate for 2 decades (number 1, yeehaw!) Lots of meth, of course, as is par for that course. The dominance of the church in local politics ensures the city has no nightlife to speak of besides bars, and thus the kids have nothing better to do than drink, fuck, and get into large-scale brawls.
City cops exist, but the city is dominated by the competing county sherriff's departments, with Potter County holding the northside, where the majority of the city (and most of it's wealth) lies, while bitter, vengeful, and broke Randall County sits in the dying south-side of the city. Interstate Highway 40, besides being the artery of all trade and traffic, also marks the border between these areas, and while local laws are identical, enforcement tactics change dramatically between them.
While there is technically a downtown, with a grand total of 5 'tall' buildings, the entire city looks and feels like an aging suburb. No one builds up, they build out, on big property lots with sizable yards. Building over 1 story high are uncommon.
Everyone is armed. While Texas allows open unconcealed carry of firearms, the percentage of people walking down the street with an openly holstered piece is higher in the panhandle. Thusly, crime in open daylight is rare, but when night falls, the streets become eerily empty, and this changes.
That's probably a lot more than you needed. Have fun!