October can be anything from beautiful fall weather to constant chilling and drenching rain. The latter is the likelier bet. Without transport, you're pretty limited in what you can do, although you could hitchhike from the ferry landing to Tlell, and hike up the East Coast and all the way around to Masset via the North Beach, then hitchhike back south.
With a rental car, there are lots of good camping options available. Depending on your budget, there are also many good B & B options.
Most kayak tour operators will be shut down by then, but outfits like Budgies Backpackers or Moresby Explorers could fit you out with gear. Again, the possibility of stormy weather makes preplanning any such expedition chancy.
If you don't bring camping and personal gear made to withstand torrential downpours, you'll be in the wrong place. If you're on a tight schedule, forget long kayak trips. Try http://www.gohaidagwaii.ca/directory/kayaking/ for information.