If I were around that age, I think I would have a harder time than they.
I imagine that if I were in their shoes at their age, I would find it more tough than they do.
ご質問ありがとうございます。
① "If I were around that age,"＝「もし私がその位の年齢だったら、」
"I think I would have a harder time than they."＝「彼等より、もっと辛いと思う。」
② "I imagine that if I were in their shoes at their age,"＝「もし私が彼等の立場に彼等の年齢で置かれたら」
"I would find it more tough than they do."＝「彼等よりも辛いと思う。」
ご参考になると幸いです。
アメリカ合衆国 
