Volunteering in Asia forum

I leave for 60 days in Thailand in a month. I am 24, solo female traveler (I have no doubt i'll meet with plenty doing the same to enjoy company with ). This will be my first time out of country. I had signed up to teach Eng in Phuket for the first 30 days and then wing it for the next 30. My plans to teach Eng have since fallen thru. Now my whole sixty days is OPEN. I'm on a tight budget. I have few things in each region id like to do. Should i hold most of my cash on debit card? Do you have any hostel location suggestions?? Are there any must sees that aren't in the typical guidebooks??
Thanks for your time!