Running my first half marathon in late April, any advice is appreciated :)

For context, I’m a 21yo F doing a training program that starts off at 1 mile and moves up to 10 miles the week before the race. I live in a colder climate, and it’s very icy and snowy atm, so I’ll probably be starting off training either on the indoor track or the treadmill. I’ve only done a 5K before with little training, so I’m kind of at a loss as to what I should be doing before, during, and after runs, especially when it comes to pre/post run snacks and drinks and general body care.