Null encoding is entirely uncovered by the CSV format - if you want to communicate nulls you need to have an internal convention - some sort of reserved string. Quoting characters are pretty commonly agreed to be " (aka ") and escape characters are technically unnecessary. Deciding to support \\ and \n is a pretty nice thing to do since some producers and parsers will erroneously choke on mid-string newlines but the only character that actually needs to be escaped (the double quote) can just be doubled up as per RFC4180[1]. The indecision on escaping means that the literal character sequence "\n" is very hard to represent in CSV consistently this is an unfortunate malus of C programmers getting all up in the standard.
RFC4180 is an after-the-fact RFC to try and codify common practices in the industry so some tools may refuse to conform to it - but it's really clearly written and like... super short. If you've never read it just go ahead and do so since it lays things out with exceeding care.