welcome to the binary world.
as trevor said, php is surely not dead. Take a look at WordPress which is currently used on ~50% of all websites.

In the end it doesn't matter, once you learned how it all works you can learn and use any language in the matter of days. I have 10 languages which I can use on a professional level.

the most important is to understand on how it all works behind the scenes. What happens when you open a website, what happens if you Post on Steem. There's a lot to go through.

Feel free to get in touch for guidance.

And most important after all: enjoy doing IT! ;)