Answer by
LeheckaG (1826)
Your additional-steps require a (concrete/masonry) footer or foundation for support.
Depending on the rise & span, pre-fabricated stairs or a "kit" are easiest.
You at least need to obtain:
(3) stair-stringers
sufficient lumber for the hand-railings & steps
appropriate-fasteners (bolts&nuts, nails, reinforcing-plates, screws, ...)
If you are cutting the lumber yourself,
you need a good-saw & a miter-box (for hand-railing-supports).