FWIW my first big mountain experience was Whistler and we got absolutely dumped on. So was definitely a new experience. I had been riding for a while and was about your age. It was huge, expansive and overwhelming... but it was a blast.
Now of course the snow had something to do with it.. but we brushed up pretty hard on the mountain before hand, read everything we could and as a friendly affable bunch, chatted up with locals in the least possible annoying manner to seek advice on best way to tackle the mountain.
I thought we managed fine.. our last day we even had a dude bring us to the peak chair perfectly timed before word spread that it was opening.
The only other thing I would mention is getting there... direct flights out of newark to jhole this year, not bad. Looking into heading that way for the first time myself.. just wish i was completely healthy.
By the looks of it whistler keeps getting dumped on. I got a report this morning 71 inches in the last week, thats insane I wish I was there right now. My buddy went to whistler last year as his first big mountain expierence and absolutely loved it not one negative comment. Ive been looking at flights to BC and its not that bad.