Create a macro in C #

Question

Create a macro in C #
Hello, I do not have as much knowledge on how to program in C #, therefore, I ask you for this help.

I need to create macros that by pressing a key, a large set of messages comes out and these are produced as quickly as possible, for example

If I press the F1 key, a macro-type message will appear in which I write `` Hello '' and it will be sent automatically without the need to press the enter letter automatically

If I press the F2 key, it will send a message that will send the following letters separately but as quickly as possible, for example H (Enter) E (Enter) L (Enter) L (Enter) O (Enter), and if I put it in a Notepad will be evidenced like this

Press F1: Hello
Press F2: H
E
L
L
O

(And that this happens in the smallest possible milliseconds)
Thanks.