Hello, I am new around here. I have been wanting to make a fmv game for many years (from real images). I have no problems with scenario, editing, music, etc. but I don't know how I should follow a path in the multiple choice situation. I looked a little unity at first, but I couldn't get efficiency. I would be very grateful if you help me to reach a detailed guide or if you say “start here and test yourself”.

Thank you all in advance

but I don’t know how I should follow a path in the multiple choice situation.

Could you be more specific? This doesn’t sound like an FMV problem.

If your choices are discrete and not too high in number then you can easily model the story as a tree of scenarios. I don’t know anything about your FMV game, but it could be as simple as assigning to each node a video to play.

I'm talking about engine actually. For example, many games have been made with unity but I am looking for help where I can start a simpler one. 

In unity there is a asset name is "charles engine" but i didint try it 'cause i dont have programming.