idea creating ecommerce website?

hello i want to create an ecommerce website i want to know some idea how much should i invest , how can i earn good
currently i know some websites and i will ship from china warehouse but i need to find and some other goods like mobile phones(iphone,samsung,htc) , clothing and so on

It depends on what you want to sell. If you just want to put up an etail site that resells stuff from china - there is a lot of competition in that market so I wouldn't suggest investing too much. If you have a unique selling proposition that sets you apart from everyone else, I think that would be worth investing a little more.

It ultimately depends on your business plan!

u should start by googling "drop shippers"

Sorry to say but the only way is to trial & error - many businesses succeeded after some attempts.