I couldn't find direct answer on the internet. Both seem to give identical result, which also includes your current language settings. Are there any differences between them? Overleaf documentation doesn't mention enquote at all, which might point out that it's obsolete, but I'm not really sure.
\enquote{first text} \newline
\textquote{second text}
csquotes. So please have a look into thecsquotesmanual, e.g., section 3.1 and section 3.3. If you need more information please show a minimal working example, so we won't need guessing. – cabohah Jun 09 '23 at 13:34