After laminating, can I immediately perform another operation such as embossing or creasing and folding ?

It is a good practice to let these warm sheets sit overnight to help set the inter laminar bond as they cool. It also helps hasten the curing of the litho-offset inks by oxidation. The problems can be a cohesive failure ink in that bond causing the laminate to pop off the print in the creased or embossed area.