1)The Portal store is usually open by May 15th
2)You can send for a permit 6 months in advance of you trip up the North Fork of Lone Pine Creek. You would apply for an overnight permit, including the Whitney Zone. $15.00 per person.
http://www.fs.fed.us/r5/inyo/recreation/wild/permitsres.shtml3)There is no public transportation between Lone Pine and the Portal. But there is lots of traffic and you might be able to hitch a ride. Others have.
4)Bear Canisters are not required in the North Fork. They are recommended, though, since bears have been spoted in the past down at Lower Boy Scout Lake. The permit does require keeping food in a safe location, with a picture of how to counter balance.