First of all, Cookeville is a college town. There will be more places to eat and shop than would otherwise be available.
Baptist is mainstream. Pentacostal is screwy and everyone knows it, even if they don't say it. If you want your religion with a decent splash of liberalism, go Methodist or Presbyterian.
The idea that banana pudding is the only acceptable dessert in the South is the stupidest statement ever. There's hardly a Southerner who wouldn't ditch banana pudding for a good apple or peach cobbler, or pecan pie. Banana pudding is what you make when you either have no time or don't give a shit. It's low effort and low rent.
Country ham is really salty. Many people will soak it in water or milk before heating it in order to remove a lot of the salt. As for chicken and especially catfish, breaded and fried is how you serve it. Don't listen to anyone who says that Kansas City bbq is the best. It's not. Pass on South Carolina mustard based or North Carolina vinegar based. Any meat cooked over fire is acceptable. Bbq is pork, not beef!!
Tea. Yes on the sweetened, no on Mason jars. If you serve anything in Mason jars, people will think you're either stupid or can't afford to buy even cheap glasses. Worst possible advice. Serve drinks in glasses.
NEVER use y'all as singular. It will immediately make you look ignorant. "You" is singular. "Y'all" is plural. "All y'all" is plural and is used for emphasis, as in "every single last one of you."
Grits are easy. It's like brown rice: put them in hot water and cook the shit out of 'em. Directions are always on the container, and always work. No stress if you don't like them.
That second picture is a smoker, not a barbeque. No one cooks in a "barbeque." Barbeque is food. A smoker is what you cook it in. Bbq is low heat and slow cooking. A pork shoulder should take 8 hours minimum.
No one will think you're dying if you say you're going home. That's just plain stupid. If you say you're going home, normal Southeners will assume you're returning to your domicile. In almost 50 years of living in Tennessee and Georgia, I have never heard anyone refer to a "homegoing." There's receiving friends, followed by a memorial service. Only an ignorant-assed backwoods snake handling bunch of idiots might call it a "homegoing."
NOBODY does the Reverend James thing in church. That's just bullshit. It might happen during a tent revival. Might.
Someone is messing with you, and is being mean and stupid.