Your question implies that knowing a specific stack/language is the key to employment opportunity. From experience, I don't think that's the case. For web stuf

Your question implies that knowing a specific stack/language is the key to employment opportunity. From experience, I don't think that's the case. For web stuff, I'd suggest learning JavaScript if you're interested front end or something like Golang if you like back end. Those will expose you to the necessary concepts you need to perform in those roles without bogging you down too much in cruft. You can safely apply to roles for most languages if you can demonstrate your knowledge sufficiently.