Halo teman! I think "sepatu" is more colloquial. Even when talking about "several pairs of shoes" , "several shoes", or just "shoes", one could (I think) just say "sepatu", and to be more explicit, "sepatu-sepatu". When the grammar speech is more strict, or necessarily formal, then I think "a pair of shoes" would be "sepasang sepatu", where "sepasang" is formed by "satu" + "pasang", "one" + "pair".

I hope it helps.

Selamat belajar! :)