Hi , you can buy a stepping stone mold , either as a single stone or as a group of cobblestones , probably available at home depot or Lowe's. And buy quickcrete , a fast drying concrete mix .
Here is a long list of projects on the subject. Hope you find one to your liking:
Just need concrete and a mold such as this one: https://amzn.to/2V9YoIx
you can also make stepping stones using a pop flat lined with plastic. and use quickcrete
thank you for your answer ,but what does the" pop flat" mean -in the other words.sorry ,my skills in english are not good