The first thing I'd do is Crank it up
.. and maybe second thing as well, if you're me. Then another punt down it for last run of the day .. Yeah, I miss Crank It Up. New creekside trails look fun too.
So, What Dozer Said. If you don't want to drive, see if a service like Ridebooker can get you up there early enough / pick you up at lift close (8PM) or later.
It's fairly quick and easy to get a lift ticket at the office under GLC and pop next door to hire a bike but probably better hire bikes not far away, perhaps Bike and Bean, Summit Sports, or maybe down the village a bit at Fanatik or the like. Do book a rental ahead of time cause you'll probably want them to swap the brakes over to front/right & rear/left before you arrive.
Dunno how picky you are about your gear, but consider BYO helmet, pads, even pedals of your own. I think some places it's BYO / buy gloves. (I didn't rent anything so am not 100%..)
Trailforks is good for trail research. Youtube vids, perhaps.
Any other recommendations?
Yeah, spend more than a day there. Consider telling your boss and family you're staying until Crankworx is over.
Hire an Enduro bike and do trail rides too: A couple of hours around Lost Lake and the Zappa trails .. get you warmed up for Comfortably Numb. Head over Westside / check out Cut Yer Bars, A River Runs Thru It, Danimal, and the million dollar - literally - Lord of the Squirrels trail, if you're up for a day out with a solid climb.
OK, so I'm probably not helping you with your stated aims, but you'll have flown to the other side of the planet and to some of the best trails - probably the best bike park - in the world ..
More seriously, if you are looking to get a local SIM for your phone and you fly via USA (IE LAX) then consider buying and activating an AT&T (or perhaps other US carrier) SIM while you're in the US - it roams to Canada and the data deals are better than the Canadian carriers offer.
Sky's the limit for food budget in Whistler, but La Cantina (mex) and Splitz Grill (burgers) are favourite cheap eats.