Hello....,Can someone please help me with node manager ? I am not able to see it in any menu.

Server : Calpheon

Town Level : 5 

Trade Post Level : 3

I am at level 73 and at North Valencia for story mission. Is there any quest i need to complete to start node ?

There was an update last May 15 they have already removed the Node Manager. You can check the announcement here https://www.world.blackdesertm.com/Ocean/News/Detail?boardNo=1140