How to format the namenode and create directory in Hadoop?

While installing Hadoop the participant must format the namenode using the below command
hadoop namenode -format.
Provide capital Y when prompted to do that .
After the above command the participant should go to the hadoop directory and from there to bin directory.
In the bin directory the participant should type the below command
./start-all.sh
After executing the above command type jps if jps commands returns all the 5 daemons like namenode, secondry namenode, datanode, tasktracker and...

How to format the namenode and create directory in Hadoop?