去野餐的说法有如下：

go on a picnic，go to （a/the）pinic; go for a picnic；

举例：I'm sure Rose won't go to the picnic because she has other fish to fry. 我肯定露丝不会去野餐之，她有别之事要做。

It's a nice day. Let's go for a picnic.天气不错；咱们去野餐吧。