When you duplicate a funnel, all its steps, the order of the steps, products, and pages are copied.
You can make any modifications you need in the duplicated funnel.
To duplicate a funnel, click the three dots (⋮) next to its name. Then, from the options that appear, select Duplicate to create a copy.

That's it. A duplicate funnel will get created.

You can use this duplicate funnel to modify any of the steps and create it the way you want.
This is how you can duplicate your funnel.