If anyone suspects that "sepatu" is a loanword, they are correct. It comes from the Portuguese "sapato".
My black shoes?
That would be "Sepatu hitam saya" - watch out for the word order.
"My black shoes" is a phrase (which form a noun), "My shoes is black" is a complete sentence.
My black shoes = Sepatu hitam saya (noun)
My shoes is black = Sepatu saya hitam. Sepatu saya is Subject (S) and Hitam is Predicate (P)
'My shoes are black' is also correct.