Follow SebLague's repo and customize to my project.
A little experiment with boids in Unity: https://www.youtube.com/watch?v=bqtqltqcQhw
For a much better implemented and performant version in Unity, have a look at the ECS sample project: https://github.com/Unity-Technologies/EntityComponentSystemSamples/tree/master/ECSSamples/Assets/Advanced/Boids/Scripts
