What kind of permits/licensing do I need

None, you should be aware of any customs requirements as to what can or can not be shipped, Also aware of custom delays

Also many companies may wish to use a escrow agent, that holds your payment till your goods are shipped or arrive, since there is no real protection if you pay and they don't ship

What u want to buy ? Could u tell me

Yes, you should have import licensing.

It varies according to the items you purchase.
And you need to communicate with our China men, and understand our business custom and ways.