Winforms: add an existing form

Hello, im doing a proyect of login, and i want to add a new formulary, but in a new formulary (form2 ) i would like to import an already existing design, i know theres a way doing right click on the part where says "inicio de seion" with the green C# but if i do that that remplaces the form1 i already have and i dont want that Hope someone can help me