To the OP, in my opinion, you being a beginner has absolutely no bearing on which configuration to choose, other than your unfamiliarity with using all options. A single pin is just as good or just as useful or just as intuitive for a beginner as it is to some of us more experienced archers.
You can tell from reading the responses in this thread is that it comes down to one thing and one thing only, personal preference. There are those you couldn’t pay to use multiple pins. There are those you couldn’t pay to use a single pin. There are those you couldn’t pay to use vertical pins. There are those you couldn’t pay to use horizontal pins. As idiotic as there reasons may be to me, my reasons may be just as idiotic to them. One thing they/we have in common is that we’ve (presumably) tried them all or most and, for personal reasons, have landed on our preference(s). Enjoy the journey my friend.
Personally, I prefer a 3 pin verical. I recognize the benefits of all varieties. I find the vertical to be less cluttered. I can set my 3 pins to the yardages I desire and use it only as a “non-mover” most of the time. However, if I have time to dial and the need to dial, I can do so.