How to make my products appear in chronological order in the proposal ?

If the service is packaged, the question does not arise. The client only sees the package with the description you give.

When the service is not packaged, the proposal in print mode (as opposed to edit mode) sorts the services by start time, with the rooms at the end. By configuring the times you can therefore define the order you wish to display to the client.

Go to the Venues > Products > Edit a product: determine a default schedule. These times can be modified in each proposal on a case by case basis.