For the masc presenting cottagecore lovers here's some things I've collected, including shops, advice and pics (mostly taken from the subreddit for posterity):

Suspenders, dungarees or overalls

Vests!

Corduroy pants and sweaters

poet shirts are often nice and light and cottagecore for warmer weather, linen shirts as well

floral-print button-down shirts, accessories like enamel pins, mushroom or flower necklaces, canvas satchels to carry your stuff, cottagecore-print face masks.

Check local thrift stores!

Plaid, gingham, linen shorts and pants, brown or straw hats, waistcoats, leather boots, thick sweaters, Nordic patterns

hobbit/hobbitcore searches can round out the cottagecore selection, also check out farmercore or edwardian for the fancier side of masc and even light academia

Etsy is your friend, support local artists directly!

Edinburgh Woolen Mill for Tweed.

Cottagecore Closet has a great selection of men's clothing

ASOS for cable-knit jumpers.

Masc cottagecore Pinterest board

imgur album for inspo, with many body types

That's all I got for now, more later, probably.