Running multiple containers application

hello there , i’m working on a security project and i’m using docker , the purpose of this project is to make sure that containers are secure , so i’m simulate a web application , 3 sites , an e commerce site , a checkout site , a bank site with a database for the bank in another container , what’s the best way to do that , and how ??? if anybody can help please respond , here’s my e-mail : , i really appreciate your help guys