Rather than constructing your own UI and interactions from scratch each time, there are plenty of UI and dialogue systems available for Unity. One powerful, free, and open source dialog system is called Fungus, which uses a visual flowcharting approach to dialog design:
Figure 1.14 – An example of dialogue generated by Fungus
In this recipe, we'll create a very simple, one-sentence piece of dialogue to illustrate the basics of Fungus. The preceding screenshot shows the Fungus-generated dialog for the sentence How are you today?.