Balzack

indeed

a pair of a pair of scissors

2 pairs of scissors.
A single blade from a pair of scissors is a “scissor”. A pair of this is a pair of scissors.

Can I combine 2 knives and call it a pair of scissors then?

Nah. That’d be a pair of knives.
A scissor is a certain shape with the finger/ thumb loop at the end.

So, If I theoretically make holes for fingers, then they can be called scissors?

Well… you’d need to modify the blades. Best to start with thick blades. Then add the loops for digits. Then drill holes. Make sure the blades work together and attach the two together so that they can act like a pair of scissors.
Or you could just start with a pair of scissors and cut out the engineering steps. It’s kind of like not building your own car, but paying a car manufacturer to do the work.
Perhaps you could buy scissor blades in bulk with the swivel/join mechanisms and sell them as “build your own pair of scissors”.