If you are referring to the notifications that you have new replies go into your UserCP
and then Edit Options
, scroll down and enable Subscription notifications in header
this will show a small indicator in the page header when you have new replies.
You can also set the system to email you this information at your registered address, the setting in the options is a default setting and may be overridden for individual threads
If you just want to check your rep status etc this is shown in the UserCP