Post a picture for some better suggestions.
Whatever steps you make have to end up at least 4" below the doors threshold so water does not get in under it.
May want to concider checking into preformed steps, you can get them with the needed hand railing already installed.
Some Lowes stores stock or can order this brand.
Just to give you an idea on how many bags of mix it would take to do what your asking and also for some good info on what it's going to take.