How do you get into the new vegas city ive gone nearly all the way around and cant find an entrance can someone tell me how to get in?

Questing, Buying Special Items, Becoming a hoker/Giggalo... theres no instant access. Walk around and grab some missions and talk to some people... itle happen

You have to either get 2000 caps or get a passport.
If you want to get a passport I'd suggest you complete a quest from "The King"

did you get into vegas by doing that?

Starting from Good Springs Go South then east then north east

like a previous poster said, you need 2000 caps, and the only realistic way of doing that is by completing some missions. There is an NCR camp near there, go ask for work

In case you haven't even got that far and can't find the Strip itself (or maybe I've misunderstood the question) - You won't find any gate in that barrier around the city that takes you straight to the New Vegas Strip or labelled 'New Vegas' - look for one of the gates to Freeside instead, you have to go through there first.

ive made it to freeside now what?

go into Freeside proper, past The Kings, and you will see a gate to the Strip.

you can buy a fake passport from Mick and Ralph's. Or you could just pay the 200 caps OR you could just snipe the gatekeeper from afar and loot the key of his corpse.

That last one is also a solution if you get locked out of the strip through that bug.

http://lmgtfy.com/?q=New+Vegas+Strip+fallout+wikia