Can someone tell me what the second season is about and do I need to complete the story of...

I also want to know

As far as I remember the 1st season focuses more on the main couple while the 2nd season and 3rd Season focuses more on the story of 2nd couple. Both of these couples have still appearances from different seasons. It's not a stand-alone so for better understanding of the characters, plot, and backstory it's better to start from season 1 :))

Thanks a lot for answering.