In order to upload your website you will need FTP access. You should be able to find the details for this in your control panel.
It will be an address you are a username and password.
The address is likely to be something like ftp://ftp.yoursite.com
You should be able to type this into internet explorer, and it will ask you for a username and password. If you enter your 1-2-3 detail it should let you in.
Then you should be able to replace the files that are currently on there with the new ones.
Google will only find your site if you have other sites linking to it, or you submit the url to them. You can submit it at : http://www.google.com/addurl/
I hope this helps.
Please let me know if you need more detailed instructions & do not hesitate to contact me if you have any questions.