You make the leap one file and class at a time. Choose to build an application. Think of the minimum viable product. Start small. Have a grander vision and work

You make the leap one file and class at a time. Choose to build an application. Think of the minimum viable product. Start small. Have a grander vision and work toward that. I start almost every app with a "hello world", usually in an index.htm or index.js or whatnot. Then I work forward. Also part of the trick in transitioning to full-blown software engineering is learning the tools: source versioning (SVN, git... and git is terrible if you already feel overwhelmed), build tools, IDEs, databases, app servers, etc. Also with Eclipse, you can focus on basically two menu options: File > New ... and Run