did you change the password given in your email? try using the one they sent in your Welcome email.
In FileZilla. click the “Site Manager” icon, select “New Site” and enter any name for this site, then enter your website address; however, do not enter the “http” and “www” portions of the address — for example, enter “MySite.com,” not “www.MySite.com.” Leave the port as “21” and the server type as “FTP,” but change the “Logontype” option to “Normal.” Enter the FTP username and password that you’ve retrieved from the “FTP Accounts” section in your 1and1 hosting account. Click “Save and Exit.” To establish a connection, click the “Site Manager” icon again, select your website and click “Connect.”
Something I found on the web. If you still get stuck then I could help but you would have to send me some details via email