It's 1am PST, and I'll be at Squaw Valley for the first trip of the season in approximately 8 hours...I can't sleep I'm so excited...haha. You're lucky you're not buying skis...I just dropped $600 on skis and bindings. I haven't even thought of boots yet.
Alright...back to the problem at hand. Most skiing clothing is designed around the sport. I can't think of any other activities besides sledding where that gear would come in handy. The coat is usable all the time, pants not so much.
Also, I'm not sure where in the country you are, but in California I work up a pretty good sweat so I dress fairly light with layers underneath. A waterproof shell with a fleece sweatshirt and a t-shirt under that. For the bottoms, I wear a waterproof lightly insulated pair of pants with long johns underneath. Don't forget a hat either...you'll lose a ton of heat from your head so it's important to cover it up.
The gear you want should be waterproof, because as a beginner you'll be lying/sitting in the snow more than an intermediate or advanced skiier.
Snowboarding styles have also influenced most of the clothing so you'll be hip as you swish (or roll) down the slopes.
I just purchased a set of Columbia ski pants at our local Big 5 sporting goods for right under $100. Waterproof with lots of pockets and a nylon liner with elastic ankle cuffs to go OVER the boot to keep snow out. I also picked up a new Burton coat for $130 at the local mall. Thin, but made of a waterproof material with lots of pockets and another elastic skirt to keep the snow out. If you can keep dry, your trip will be much more enjoyable. Let me repeat that: if you can keep dry, you'll be much better off.
I prefer gloves versus mittens for the dexterity, and I always get something with a removable liner so that they are easier to dry. Ohh..I always wear thick socks too...for warmth more than anything...those long ski lifts can get chilly.
Other things to consider: sunglasses because all that snow is reflective and very bright (especially on sunny days), sunblock (I've been sunburned many times on the slopes), goggles (not necessary if you're just learning...a requirement if you like speeding straight down the mountain).
A small tip...try to keep any seams, pants cuffs or other folds in your pants out of your boots. It will cut off circulation to your foot and make wearing boots really miserable.
Hot chocolate, regular shoes and a fire never felt so good after a day on the mountain....best of luck and have fun.
Ed