It's pretty cut an dry. I assume you're referring to Paganism.
Well to begin with "Old Age" just means older religions and more traditional practices that associate with them.
"New Age" is formed by much younger adaptations with a bit more flexibility.
Wicca and ecclectic belief systems are considered "New Age" by most standards, Shamanism and Druidry are normally considered what you called "Old Age".
I'd say there are more "Old Age" practices than "New Age". I say this because "New Age" practices tend to kind of mush together and blur the lines between religion or doctrine specific styles and habits while older practices will usually resemble each other in many ways but by all means have their own titles, formations, names, and all around what they call things. It's like the difference between Graeco Paganism vs. Roman Paganism and Wicca vs. Ecclectic Wicca.