For clothing and souveniers there's a store on the ground floor of the Garden (arena).
Good luck Kyla.
Gary

nothing much in the downtown area they have jj teaparty and baystate coin shop left the are a sportcard store with little memorbilia and its at bromfeild st between tremont and washington st. there use to be a bigger one outside of boston in everrett called sports world i dont know if its still there since i havent been collecting in over ten years. i guess the safest bet is the proshop at the garden since they play there but you already have everything there good luck