If you want to install WordPress and use it in Punjabi, there is an ongoing effort to localize WordPress into Punjabi; see https://make.wordpress.org/polyglots/teams/ The support forums in Punjabi are not yet complete: https://pan.wordpress.org/
I tried using the Google Translator plugin, but that does not convert
the page accurately.
Google Translator is machine translation, not human; it won’t be accurate to a native speaker. And, that’s a completely separate issue than actually using WordPress in Punjabi, i.e. entering text in Punjabi in the WordPress editor.
If you want to post Punjabi text in a WordPress site installed in another language (like English), you can paste Punjabi from Google Translate https://translate.google.com/ and have it render correctly in WordPress. (I tried this myself).
If it doesn’t, something is wrong. It might be worth contacting the translation team https://make.wordpress.org/polyglots/teams/?locale=pa_IN