[Help] About Web Development

Hello, here's a junior developer, I recently started to learn web development, but I don't know what to do next. I have learnt HTML, CSS, JavaScript, TypeScript, NodeJS, React and MongoDB, some of my friends tell me that I can build applications with the MERN stack technology, but I still have no idea on how, because building a fully working application isn't that easy for me, should I make a flowchart before getting my hands on coding? Or should I learn to code some simply MERN stack projects by watching and copying from some YouTube videos? Thanks for taking your time reading this!