How to develop a online programming training website? [on hold]

I am going to develop a local website for online programming. My prototype is DataCamp or Code Academy . I want to be able develop programming assignments and evaluate result and syntax. I am good in frontend ,javascript and frameworks like React and Angular. My prefered language for the backend is PHP but other tools are O.K. too. I know how to format code editor by frameworks like code prettifier OR code mirror.However,I have stuck in the backend section. Is any Open Source code or lib to accomplish that? Thanks in Advance P.S: For the first course my Focus is on the Python Tutorial.