Leto Theme change no of catgeroies displayed in row

Hi, I reinstalled on staging site at https://staging.shopisles.com/shop/ to fix earlier issues (displaying products by error) and it now just displays categories (shop page), however they are too large (images) and I want to get 4 in a row and much smaller to style similar to this
eventually,categories|690x206

Does anyone know how to
a. resize category images (not products)
b. change no in row to 4 ?
Many Thanks

This topic seems to be a duplicate.