Here's my experience, Factory irons, while usable are pretty poor, peep sights are far superior as long as you don't over think it, but... a low power scope will "see" better at dawn and dusk or dark woods, you can pick out details such as antlers, intervening branches, etc much better, especially at longer ranges.. you have one focal point, just put crosshairs on the target, and depending on model can serve as a rudimentary range finder.
That said, a scope somewhat interferes with ease of carry levers are noted for, and too high a power makes finding things close up more difficult, I find 4x maximum, 2, 21/2 x about perfect.
For a beginning hunter a scope is easiest to use, If you want iron sights, replace the factory sights with a good receiver/peep sight, with aperture removed, My preference is a rear peep with a Williams fire site front bead, but thats me.