Me too. I do not work in IT, I do not even work at a computer.
Started installing first ripped Windows, later Linux on handmedown laptops starting around 2010.
And tweaking the shit out of it, later also to escape the Googleverse.
Selfhosting since 2014.
I can’t do everything either but I’m confident enough to let my server face the world. It doesn’t take all that much knowledge, mostly common sense.
I guess there’s some secondary knowledge, like knowing where to find useful instructions (archwiki) or knowing that Linux software often (but not always) doesn’t bother with sane defaults.
If this narrative seems to be coming from the prehistoric past then there’s your answer: give it more time. Do what you can do now, and surely your knowledge/capability will grow. Esp. tweaking Linux!