Whenever you get a new *nix environment the shell you are offered to use may not be the one you like.
To change the default login shell is pretty simple:
first, check the available shells in the system:
second, use chsh command
chsh -s /usr/local/bin/ksh
This should do it.
If your system has bash, which is my favorate, you will also need to create .bash_profile and .bashrc for the alias, promot etc… settings.
A sample .bashrc can be found here.