I went to college for computer engineering, and what I learned in college has been pretty much entirely irrelevant to my self-hosting hobby. That said, there’s a ton to learn. The good news is that all the information on this stuff is available online for free, you’ve just got to have a good search engine that doesn’t give you slop and you should spend a lot of time reading. That’s how I got into it.
Services like Yunohost are a great place to start, but setting them up will still take some searching if you’re a beginner. Generally you can find services anywhere on the spectrum between “one-click setup” and “bare metal machine you can customize to your heart’s content” so you can navigate that spectrum as you learn more. Just try to always be security-conscious, research the security ramifications of whatever you’re doing.