I would choose the ones that interests you the most. Or just pick biomes that have the most biodiversity (Rainforest, Coral Reef, etc.) Or just pick anything. Tundra, Desert, Grassland, Taiga (my personal favorite). Hopefully this helps! :)
A sample count is the data from a sample, or a small group. A total count would be the data from the entirety of whats being studied, not just a sample.
