这两者区别不大，都有“去做某事”的意思。
不过，go doing中的do一般都要求是不及物动词，如go shopping/swimming/walking等。
而go to do sth中的do无此要求，且有时可以转化成go and do sth.
如：Let me go to look at it. = Let me go and have a look at it.
