It's worth noting that Hornady ammo tends to print very high, especially the Lever Evolution rounds.
If these are the rounds you want to use, or if other rounds are generally shooting high, then you'll need to change sights.
You'll pretty much have to buy a higher front sight blade. You can replace the rear sights with a bunch of different options.
Williams and Marbles both make "standard" rear notch sights that mount to the existing dovetail. The Williams is fiber optic. The Marbles are just nicer standard type sights.
Lyman and Williams and Skinner (and probably some other companies) all make receiver mounted peep sights. They all work sightly differently, but they all work. These require higher front sights regardless of if your gun is printing high or not.
Marbles and Lyman both make tang mounted peep sights. You have to drill and tap an additional hole in the tang. Best to have a gunsmith do it if you don't have experience with it.
You should also note that most 30-30 rounds peak in their trajectory at 100 yards. Some standard sights are regulated to be a couple inches high at 100 yards, which means you're right on at 50 yards and 150 yards.
Scoping is pretty easy as most 336s are drilled and tapped on the receiver already.
The thought of putting a red dot on a lever gun makes me really sad, but it's possible. I want accurate iron sights on all my guns regardless of the presence of other optics.