Dress in multiple layers rather than wearing one heavy layer.
Avoid cotton if at all possible. Synthetics, wool, and silk are warm and wick away moisture whereas cotton absorbs moisture and feels cold.
Don’t wear jeans and do not tuck your pants into your ski boots. Also, do not layer your socks. A good thin wool ski sock or newer synthetic fabrics will provide more comfort and circulation for your feet.
If you own skis, label them with tape. Lock bindings, loop your ski pole straps over the tips and carry them as one unit.
Goggles are nice to have when they are making and blowing artificial snow.
Bring some snacks for the bus ride and extra money for dinner. The fried dough is great but not healthy. Food in general is expensive. Bring some healthy snacks for the trip to and from the mountain along with a bottle of water
Know your limits. If your friends are more or less advanced, ride the lift together, and arrange to meet back at the bottom so everyone can choose a trail that is appropriate for their own level