I would recommend Python as the programming language and as you are a new developer, Flask to start with. It gives you a solid understanding on the web patterns such as REST and will get you up and running in no time. However, I suggest you to read and study on front-end technologies like (React or Vue) and databases (SQL and NoSQL) and probably some NodeJS as well. First grasp the concepts (which Python is ideal for) then it does not really matter the language as such.