There were quite a lot of people wandering in the park on Sunday.
首先,表示某地有某物,用there be句型。。
其次,如果你可以确定每一周都有人在散步,那你可以用一般现在时。。
there are many people wandering in the park on sunday
Many people take a stroll in the park on sunday.
On Sunday,there are many people go for a walk in park.
Many people walk in the park on sundays