Would you like to order something while you're waiting?
Would you like to order something before your friend comes/arrives?
ーWould you like to order something while you're waiting?
「お待ちの間に何かご注文されますか？」
Would you like to order ...? で「ご注文されますか？」と丁寧に聞けます。
while you're waiting で「待っている間に」
ーWould you like to order something before your friend comes/arrives?
「お連れの方がいらっしゃる前に何かご注文されますか？」
before your friend comes/arrives で「お連れの方がいらっしゃる前に・到着される前に」
ご参考まで！
カナダ 
