There have been older threads going back to 2013 discussing macros but I don't feel it's appropriate to necro those threads. You can find them through a Google Search. So, instead I created this thread to 1) learn more about Macros 2) introduce Macros 3) demystify Macros and 4) share macros.
Here is what I know about macros at this point being completely new: (remember, I'm not a definitive expert on this. I to am asking for guidance)
1) Some classes like Healer require Macros. I played this game almost exclusively as a DPS but now that I'm exploring Healer, there really is no way to be a Healer without Macros. Remember in creating a macro you create a push button icon. So, you press the push on the Hot Bar and it gets the job done.
2) The Macros screen is on the System screen and it really is a streamline platform. There is a code box there to enter text. So, for those not familiar with things like Excel (I used to work as an accountant) the term Macro I associate with is something like VBA programming which is a really easy streamline language. In this game the language is way easier and intuitive especially if I can do it.
3) There are certain commands that are set like /ac which means "action" which is a physical action like a strike or a heal. So, for WHM the primary healing spell is Cure. So, to signal to the Hot Bar Icon created to Cure you would type in /ac "Cure" Replace "Cure" with any name of the action on your Hotbar and it will do that action (for archer as an example it could be "Straight Shot").
But that action needs a target so the third element of the macro is the target. So, for example /ac "Cure" <2> means Cure the second person in the party with /ac "Cure" <me> being yourself in the game. So, for a healer there would be four buttons to Cure yourself and three members of a party. This prevents you from having to click on people to Heal them, especially if everyone is crowded together. (remember you have to literally click on people to cure them, except if you use this set of macros. <me> needs to be there otherwise you will have to click on yourself)
As an emerging Healer this is the only macro I use. Another would be similar for "Esuna." Example: /ac "Esuna" <3>
This is the bare basics, but it can get much more complicated than this for things like rotations in other classes.
4) What typically happens in these old threads is people share code they created. So, please share code you created.
Thanks for the help and thanks to anyone who participates.
TL;Dr
Share Macros for individual classes and tell us what they are supposed to do. I myself need Bard and Healer Macros, but others will have different needs. Ask questions about Macros so others can answer them, Macros are not intimidating once you get to know them.