Hey there, thank you for playing my game!
The major plugin I used with Unity was Naninovel, which basically support the implementation of everything expected from a Visual novels. Menus, text box etc...
I'd recommend for you to ask yourself: Compared to Ren'Py (the oldest and most popular engine and for a great number of reasons) what is it that Unity does Ren'Py cannot do, or as easily? Do the pros outweight the cons?
Good look in your VN-making journey :)