Given that the first plugin you have asked for here is a 3D battle system plugin, I suggest it is going to take a l-o-n-g time if you don't already know how to program.
Consider that there are a number of excellent programmers here, who have been programming for many years, but there are no 3D battle system plugins.
If they can't make one, despite their years of experience, that should give you an idea of how long it's going to take someone who can't program at all to first learn the basics, then apply their knowledge to slightly harder tasks, before being able to take on something like this. Also consider that there may be no 3D battle system plugin because those who might be capable of making them could just think it's too much work for the results they'd get.
If you study programming at university, you would be capable of doing some fairly basic stuff after about 6 months. That is based on maybe 3 hours of contact time with your lecturer/tutor plus 8-10 hours of personal study each week. If you are able to put in more time than that (say you're doing a Udemy course and are not limited to someone else's availability), you could progress faster. But it's still fairly basic stuff that you're learning.
Once you have a handle on the syntax and can create programs that run well and without bugs, the next thing to do is to look at MV's code and see how it does things. That'll be your start to learning MV's data and class structure, which you'll need to know intimately in order to build anything with a degree of complexity.
Be aware that the battle system is probably THE largest and most complex system in MV. I suggest you pick MUCH more simple systems and learn how to do those first, and work your way up.
Otherwise you're like a mouse saying you're going to eat an elephant for dinner. Likely unaware of what a massive task you have decided to take on.
The fact that you completely ignored the answer you were given in your other thread, and your response was "don't worry - I'll learn to code and make one myself" also points to you having no inkling of how difficult it is to do.
You can do it within a year if you're dedicated enough. If you learn how to program, the rest is just learning the language specifics, after that, you can learn MV while working on plugins. Otherwise, nothing you learn will stick.
So, if you want to learn and improve, pick a project as a foundation for learning a language.
If you really want to understand what is going on - and that is needed for 3D-programming - you'll need a good basis in mathematics, logic structures and the other fundamentations of programming. If you don't have that already from your schooling, ad a minimum of another year to learn that before learning programming, and you'll probably need more than a year for learning programming to the level required for 3D-structures.
There is a reason why even professional companies go to use existing engines, simply because it is too much work to program the basics of everything for every game they create - but that also means the user is limited to the options of that engine.
About a week, but I already knew programming as I'm an ex-Computer Science Major. But when I was first learning programming I learned most of the basics over a spring break where I got *really* bored and borrowed my father's how to program C++ book. And by really bored I mean I spent the entire week reading the book and working the exercises. But, by the end of the week I knew the basics of C++!
However, I also already knew the rules of logic and mathematics required for programming before doing that. Just know there's a good reason most schools require you to learn Calculus I, II, III and Linear Algebra as part of a programming degree, and yes, you will need Linear Algebra to do 3d well. So don't forget to learn those 4 topics as well as the programming, especially if you want to do more than just behind the scenes edits via plug-ins.