Having done both if the stairs figure out to more than 20 bags of concrete i would suggest calling a redi mix concrete company.
How to build concrete stairs against a wall.
Use a masonry bit to drill through the 2 x 4 and into the concrete floor then attach the 2 x 4 to the floor with concrete nails.
Building concrete steps can be done by mixing the concrete from bags you buy or calling a redi mix concrete company and having them deliver the concrete pre mixed on a concrete truck.
Some local building codes may require that you anchor concrete steps to the foundation wall.
The first step no pun intended is to mark out the area where the steps.
You can either drill at an angle into a poured concrete foundation or through a concrete block wall and insert rebar in the holes.
Building concrete steps requires a knowledge of mixing and pouring concrete making concrete forms and using tools like hammers drills levels and so on.
How to make brick or concrete patio steps for your garden the guide to building steps with pavers.
With an underlying grid of 1 2 inch rebar poured concrete steps will give you years of low maintenance service.
Position one stringer against the wall and have a helper hold it in place.
Fit the treated 2 x 4 into the notch and press it flush to the wall.
If this is your first project using concrete you may want to practice on a simpler project instead like pouring a simple concrete floor.