Do you know about Timeline? It’s pretty handy for making cutscenes!
https://docs.unity3d.com/Packages/com.unity.timeline@1.2/manual/index.html
Otherwise, if you insist on reinventing your own Timeline, you could just make a ScriptableObject[ ] array
and be done with it.
Then using interfaces you can have a common way to get at each one you find.
Using Interfaces in Unity3D:
Check Youtube for other tutorials about interfaces and working in Unity3D. It’s a pretty powerful combination.