Self-study developer guidelines. This isn't fast, but it is quality.
My name is Christopher Bloom and I'm a Principal Engineer at Knapsack. Over my career I've launched thousands of sites. I also spend time every week mentoring and tutoring new developers, helping dozens land jobs in the tech industry. What follows are resources that roughly form a crash course journey into development.
Fundamentals are a good place to start.
CS50: Introduction to Computer Science
A light introduction to webdev concepts.
Do every section. Each is valuable and focuses on web tech. Complete many real projects.
While working through the projects included in the Free Code Camp material above, teach yourself the extremely important concepts of version control.
Learn git concepts, not commands
Lots of tools and processes that all developers are expected to be competent at.