What would you guys recommend if a beginner wishes to become a full stack developer?
I have some basic programming knowledge, but can't say that I know enough to be a dev.

Learn Lisp, read the postgres manual, think it thrice before using a NoSQL database, get on React + Redux, grab Bootstrap until you're comfortable with the quirks of CSS and... Oh yeah, *NIX sysadmin. Learn to create chroot's and jails (FreeBSD handbook might come in handy). How to configure a server and execute software with as little privileges as you can. Debug enough software that you feel not extremely weird doing it, read a lot of source code on public repositories, don't just bloat everything with countles dependencies (and if you need to do, please review them). Know how to detect intruders, attacks, etc. Mmm... Guess that sums it up.

Oh Haskell would do some good too, and proper data modelling. Also, try to focus and develop some intuition. I'd really like to elaborate on how important it is to learn both Haskell and Lisp. But not until you use them will you be able to appreciate it. Try with http://cse.chalmers.se/~rjmh/... or Paul Graham essays for insight on why functional programming might matter.

Becoming a true fullstack dev is a loong way. I think it is more important to have at least one language you really master and then go on to learn new stuff.

Don't try to know multiple stuff at once.

Full stack was never a goal for me. I wanted to be a developer, so I kept learning programming. I eventually got stuck in web development (another rant...) but never had any DevOps or database people to help me set up the backend, so I started learning just enough to set up my own projects. From there, I learned more while wearing those hats at work -- management was often too lazy/cheap to hire actually experienced people, and relied upon me instead.