Congrats,

It's a top notch operation in Denver. Everyone is happy to see the new faces in class. Everyone wore business casuals to class (no jeans) for the two weeks of indoc. You'll have a break after that before you start a/c specifics so it should be sufficient to pack for one or two weeks as you'll get a positive space ticket home for the weekend while you're doing indoc as well.

Bring a suit for your company dinner where you'll eat some great food and be presented with the UAL wings.

You pay for the hotel. Cost anywhere from $50 on up unless you wanna share a room with someone. There are apartments for rent short term but you probably will need transportation then. Cars can be rented for around $18-$20 per day.

Only downside is the pay is below par pretty much coming from anywhere.

Good luck and welcome to United!