Or, even better, find a server/hosting company/datacenter, and insist on interning/working for free/peanuts as a NOC Tech. You'll learn all the SA/networking/Linux/DNS etc fundamentals for sure, and it's a great foot in the door into the tech industry. If you're half way decent, you'll move up the chain quickly.
You're going to learn the best by doing it with your hands.
It'll cement what you're learning from the training.
I like the mindset of people wanting to learn SA/fundamentals though. Far too many are skipping the needful whilst diving straight to cloud/serverless.