thanks for the Review I already fixed some of your issues like closing the Inventory with Esc and also pausing the game, but I had a hard time understanding some of your questions since I don't speak France I had to use google translator.
How to build stuff.
to build something all you have todo is
1.Gather all the Resources.
2.Open the BluePrint tap in the Inventory.
3.Click on the Item you Want and can Craft.
4.After the Item is in your inventory simply Left Click on it and it should pop on in Game, now left click agin to place the Object.
I'm gonna add like a info text wich says "Left Click to Place"