Stage 1 (beginner level): Panic and call your hosting company.
Because you’re a beginner. And for some reason, English in technical jargon just Does Not Compute. To you, “Error on line 41 in askdjf2fj-sldfkjsfaf.php” means “OMG I JUST BROKE THE SITE HOW DO I REVERSE IT.”
Stage 2 (after a few months): Google.
After a few months, you start to realize that the hey, the error messages actually contain meaning, and other people have encountered similar errors! If you can’t undo what you just did to get the error, you copy/paste it into a search engine. Half the time you find nothing helpful; the other half of the time, you find something, but don’t understand enough to find the Stackoverflow solution helpful.
Stage 3 (after a few months more): You read the error like it’s English.
… And you understand enough to decipher the meaningless jargon the screen sometimes spits out from what’s really important. Then you go ahead and find the right file and fix the corresponding error. Sometimes the instructions for what to do next (like when there’s a merge conflict in git) are output directly into the console, yay!
Stage 4 (a year later):
You know when to attempt a quick fix, when to google, when to ask for help from a co-worker, and when to say “to heck with it” and restart your server and rebuild your database. You don’t panic anymore, because you know that somehow, somewhere, at some point it will be fixed.
Okay, this is a somewhat tongue-in-cheek story of what I’ve been through with error messages. I’m learning Django now, and suddenly I’m looking forward to a lot more server-issue-related messages. I still don’t like them, but I panic a lot less now.
And I’ve stopped calling my hosting company.*
*Yes, I am embarrassed to admit this did happen when I messed up some PHP on my first ever self-hosted WordPress site. This was before I even knew CSS, okay? Okay.