How to create a new cinematic ?
1. Set-up a Scene
1. Create a new project
Attention: Don't do your cinematic in your main addon /!\. This could create conflicts and it will add useless weight for players.
With a cinematic addon, you can add dependencies without worrying too much about your mod being buggy, used only once or a few times.
Attention: Don't publish to workshop a Cinematic addon, it's useless.
2. Create a sub-scene of your world
Create a sub-scene of your cinematic world and save it in your Cinematic addon.
3. Create a 1st Scene
Pour ce faire, allez dans Cinematic Timeline puis Add Scene et donnez lui un nom
Don't forget to set 16:9 aspect in Camera/View Aspect Ratio 
Once that done, you can continue the tutorial 👍