Happy festive season!
I know I've bought it on my Wii U VC and really want to play it but my life is busy as hell rn.You should play the first one. It's really great, and it remains to be my favorite Paper Mario game. It won't have the same focused story as Super Paper Mario, but it has enough to get you invested in it. And for its time, Bowser beating Mario and seeing increased interactions with him and Peach really was something special.