Welcome to HF!
Um, I'm not sure how much you know, but typically we say "Mares, Geldings, and Stallions".
Obviously, stallions are not for beginners.
I personally like mares, but most people don't. They are challenging, smart, and generally a rollercoaster of emotions, which can be good and bad. They are very expressive, which is great for liberty which is what I have gotten into.
Geldings are generally more obedient, relaxed, and don't test you as much.
However, each horse is an individual. There are always exceptions to generalizations. For instance, my mom's mare is fairly newbie friendly, and acts more like a gelding. She isn't moody.
I saw your other thread. I recommend that if you haven't already, you find a trainer or coach who can teach you about riding and all aspects of horse care, and help you find a horse appropriate for you. Horse ownership is not something you want to dive into head first. Test the water and enter slowly
God Bless you and be safe!