start can be followed by -ing or to... with little difference or no difference in meaning. For example, It has started raining~It has started to rain.
But we normally do not use -ing after -ing:
It s starting to rain. (not It s starting raining)
这人兄解释得很好, 直接copy过来了 = W =
别见怪 = W =

Start to do sth也可以是Start doing sth