Macroquest is like the foundational platform.
Very Vanilla is the flavour of Macroquest that Redguides supports. There are other flavours of Macroquest
User functionality (information, communication, quality of life, and automation) is delivered by plugins and macros.
Plugins are applications (in the classic sense of the word)
Macros are scripts (uncompiled code)
In general, something that is more technical in nature (eg navigation) will most likely be solved by a plugin whereas something more customised or general will be solved by a macro (eg re-order my inventory)
There are many different ways of solving ‘your problem’. Several plugins and many macros do similar things and have overlapping functionality. But broadly,
1) EQBC or
MQ2Dannet handle communications (command and control instructions) between clients (tell character Y to do something from character X)
2)
KissAssist,
MuleAssist, and RGMercs are the broadest multi-class solutions for character automation. There are others like XGen and Modbot. CWTN and Sic have an (ever increasing) range of excellent class specific plug and play plugins
3) there are a range of information plugins, like DPS trackers, kill trackers, status (aa, tribute, invis), and
4) a panoply of macro resources, like explorer (run around the world), bag sorting, mission flipping , and fishing
Read a lot, as others above have said, there a bunch of guides, and an active discord group for ‘phone a friend’ or ‘ask the audience’ when a problem is stumping you.
Enjoy.