I would recommend the caro-kann. It has stronger foundations and structures which can be useful at all levels. It is a bit richer in themes and ideas, and less likely to be refuted.
here's a recent game by Hikaru Nakamura using the Caro-Kann.
and before splurging into courses, look at chess.com videos and also on youtube.
For instance, this video may be useful before you decide to go for the caro-kann. Take a look !
From what I’ve read the Caro-Kann and Scandinavian get recommended for those in my situation. Both have a Short and Sweet Chessable course which I’ll use for my study. Which do you recommend? Thanks