You'll need to have a pair of gym shoes to work out here.
You'll need to bring your own shoes for the gym.
この場合、次のような言い方ができますよ。
ーYou'll need to have a pair of gym shoes to work out here.
「ここでトレーニングするには、ジム用の靴が必要です」
ーYou'll need to bring your own shoes for the gym.
「ジム用に、自分の靴を持って来る必要があります」
ーYou can't use outside shoes here.
「ここは土足禁止です」
ご参考まで!