Oh dear, referring a noob to vi ... without at least explaining some basics like
:q! ... is kind of cruel
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But in all seriousness, OP you might want to try the command
nano first. It's another command line text-editor that's a bit more friendly than vi, but I don't know if it comes preinstalled on Steam Decks.
You could also use the commands
cat, which will just output the entire log file to the command line, or
tail, which will only output the end of it.