The course by itself can introduce you some technology. You have to get some experience with at least some labs also.
I did the Networking Academy https://www.netacad.com/ from Cisco, 15 years ago. 10 months lenght and that changed my life. Today they have other topics, not olny netowkring, as automation, development, operating system.
You can make very short trainings, most of them 5 days for some vendors that can give you very interesting knowledge. But I have to say to you, a certification is another step that can give you more visibility into the market and better chance to get a job with a good/average salary.
There are some trending topics into the market: