Now that you have logged into your server via ssh your all ready to navigate around the command line. You start out in your home directory. This is a location for your to store all your personal files. You all file permissions to create directories and files here. In linux most users do not have permission to create files and directories everywhere. One user known as root has full permissions. We will get to root later.
To see your present working directory use the pwd command
pwd
/home/username
notice is linux that directories are preceeded with a / instead of the windows \ . Different directories can be on different partitions or hard drives but they all have a path that starts with /. You can see the partition or hard drive layout with df -h (disk file -human readable)
df -h
If you wish to change directories then use the cd command
cd /location
or cd .. to go one directory lower or cd . to stay right where you are.
One important command is man it stands for manual you can find out detailed information on any command using man for example
man df
Will tell you all about df.