Multiple use of a void OnStart, need help D:

[Ermu]

Under your line //new thing here is a code block that is out of place. You can't stick blocks of code arbitrarily around, they need an identifier, which essentially says what it is and/or under what circumstances it is run.

Yeah, but that part needs to be with void OnStart(). I guess void OnStart() is an indentifier? But if I put void OnStart() there it says I can't put void OnStart() twice...

You can do this:
put this inside your void OnStart
NewThing();

and then place this anywhere, outside OnStart, OnLeave, and OnEnter

NewThing()
{

}