Leok, you are not the first person to be confused by the title of this forum. The term "backpacking" in the USA means wilderness trekking, not the European definition of budget traveling with a backpack. A lot of us have done the latter, but that's not the real purpose of this site.

A better forum for you than this one would be Lonely Planet's Thorn Tree. It's not quite what it used to be since the BBC took it over, but there are still a lot of regulars there who give good advice. I would suggest, though, that first you do some research, as in going to the library and reading a few guidebooks, so that you can ask more specific questions.

Only you can decide if you want to spend a lot of time traveling from place to place, trying to see everything but not able to do more than glance at a few famous sites in each place, or to spend most of your time in just a few places exploring them more thoroughly. (I've done it both ways and far prefer the latter, but I can speak only for me, not for you!) And only you can decide how much or how little you want to spend. These are not questions that others are qualified to answer, simply because we don't know you, your likes and dislikes, or your budget.