Procedures to writing script in ns3

1. 
   Including necessary files
2. Use appropriate namespace
3. Set simulation time resolution
4. Enable logging for different modules
5. Creating codes
6. Create net devices with MAC and PHY
7. Attach Net devices to nodes and set interconnections
8. Install protocol stack in nodes
9. Set network address for interfaces
10. Setup routing
11. Install applications in nodes
12. Setup tracing
13. Set application start and stop time
14. Set simulation start time
15. Run simulation
16. Release resources at end of the simulation

source: https://ns3tutorial.com/ns3-tutorial/