If you want to develop for ODTN project you should first get ONOS . Please follow the instructions in the following link to setup development environment for ONOS:
Development Environment Setup
And the following link describes a simple "local" workflow where you build and run ONOS on a single development machine.
ONOS Developer Quick Start
Note 1: For ODTN development purposes you should checkout master branch.
Note 2: Before launching ONOS please export these apps:
A good starting point to get familiar with ODTN project is using ODTN emulators and ONOS together. You can find more info about that here:
Then you can follow one of these guides to setup a phase 1.0 demo as a base: