Are you able to login if you go to
https://x12.x10hosting.com:2222, note that you should then use the hosting username and not email, if you click the "quick ftp" on the sso page it should tell you the username if you are unsure what it is.
On ftp, what error are you getting, if any? Are you using the default ftp account or one you created? What are you using as hostname?
Assuming you try to access from the same IP as you posted here it is not blocked by firewall or anything like that which is a common cause for login issues.
As for the blank page, if your script is not fully up to date you may have to change the php version to an older one, default for all accounts are version 7.2, and some depreceted functions, such as mysql_connect for instance, has been removed from that version (if I'm not mistaken it was removed with 7.0 coming out).
Also you might want to check that database host is set as "localhost", that is currently the only option that will work.