1.我和家人每天都会去散步，在途中我们会买上法式糕点 2.世界上有我很多朋友，我在假期时常常找他们玩

Correct grammatically, but not lexically.

As with other comments, it is better to write the first sentence as "每天和家人在散步中, 我们总是买些法式糕点"

We don't say "during the walk"(散步中)， we say "on the way" (路上)。 So it'd be 路上我们总是买（一）些法式糕点。 "散步的时候", as Peggy suggested, would be acceptable too. Just a bit repetitive, as two 散步s are so close in your sentence. Your 2nd sentence is OK. I would change the order, and say 我在全世界有很多朋友

我会这样说： 我和家人每天都去散步，散步的时候我们总是买些法式糕点。 另外那句很好～