Do i need wireless capability on a laptop?
Yes, if you wish to use your laptop away from home using someone else's wifi network, or using a hotspot. At home, rather than wifi, you could use an ethernet cable to wire directly to your router.
laptop has capability of recieving wireless internet, so what do I need. the connections in area all require a code.?
There is no best wireless laptop provider. Wireless capability is a feature included in most new laptops, but they would all use either 802.11g or 802.11n. The best wireless you can get built into a new laptop now is 802.11n (or just wireless n). You will get the most speed and range with the N. If by provider you are talking about wireless broadband cards for laptops, the best bet would probably be AT&T