Get some bids from local contractors. A stoneyard or quarry can give you the names of contractors they deal with. Thos contractors can tell you what you have to deal with if you decide to do it yourself.
Wood stairs might be a less expensive option. Maybe even an electric tram. Stonework is expensive. More so, if flat stone is not locally available.
Another option is to make concrete stepping stones, exposed aggregate or smooth, and then dig then in to place up the hill. Start at the bottom. They should be at least two feet wide and a foot deep.
You should list where you're at.
Mike..retired contractor.