Do you mean trading in person, or just buying things from market stalls?
After a bit of crafting at the farm, I tried a bit of fishing at the Peaceful Ocean Market, a location hosting a tournament for the next 2 and a half days.
I caught 6 fish, turned all into chowder, and got a box of branches.
Zero points so far, and 8 branches I don't know what to do with. Are those used with the new grapevines?
Attempt 1 is a bit of a bust, but the month is still young.