import a project into another

Hello i want to put all the works i have done in a previous project in a new project i create for th epourpose

Can you please explain me the procedure?

do i just need to open all the bins of the old project into the new?

or i need to copy them from the actual folder where they are stored?

in few word i want to make sure that when i'll delete the old project folder i have ALL and EVERYTHING in the new project folder

thanks a lot