One trope you’ll see repeated all over anime, manga, novels and even in real life is that of the ボケ (the idiot) and ツッコミ (straight man). Once you know a bit more about its dynamics and some of the more famous 芸人 duos, you start seeing it everywhere.
Downtown is one of the more famous ones, but if you want a shortlist of some of the most famous and relevant duos, the M-1 Grand Prix as well as the contestants of the Documental streaming series are great places to get into Manzai.
Manzai is certainly one of the most relevant media in Japanese, and it is so important you start to see language trends as well as cultural shifts reflected in manzai performances. At the same time you also get to see manzai actively shape Japanese culture and set new trends. It’s a great step if you want your Japanese to improve considerably and get closer to real Japanese humour.
I remember the show on Netflix about two guys starting their manzai act. I think it was called Hibana Sparks.