We highly recommend that you book your first night of accommodation from home. It's never much fun to find yourself in a new country, in an unknown airport after having flown for several hours, and not have a place to sleep.
We always recommend that you book accommodation at every new destination you arrive at, after long flights, and, as a minimum, at your first destination after you've left home. You don't have to book more than a single night if you prefer to go out on your own as quickly as possible and find a place that suits you. Or you can book 2-3 nights, see the city, and move on - it's all up to you.
When traveling on a backpacker budget you will most likely be looking for hostels and similar cheap accommodation. The standard, services and amenities varies depending on your destination, but generally speaking you should not expect any luxury suites unless you are willing to pay the price at a genuine hotel. If you are planing accomodation without the help from a KILROY travel consultant, make sure to check what other people say about the hostels you are consindering. Online blogs are a useful tool for this kind of research.