( lol )
If you want to see your default shell, take a peek at
/etc/passwd. So if your username would be 'joe':
$ cat /etc/passwd | grep 'joe'
(You could leave the "| grep 'joe'" part away, but what if your passwd file is extremely long?)
Your default shell should be somewhere on that entry that describes your username.
But If you want to know what kernel you are using,
try
$ uname -h