Tracking Custom Events using GA4 and Google Tag Manager

I would require to setup some custom events and conversion e.g how many people are using our product trials, out of those how many moved to premium version? Also, I would like to see what revenue we are gathering? How many of the visitors dropped after the 14 days free trial have been expired and so on.

Please only BID if you have already have a good sound knowledge of the things. As I have good knowledge of Universal Analytics but not of the G4.

Thank you