Yes, every game has already the map of its predecessor and introduces a new part. So yes, the Old World is in Warhammer II and you can play it in the "Mortal Empires" Campaign, where the Old and New World are combined.
There are continents like in the real world and they also look familiar. For example the big jungle continent Lustria is based on South America. Something unusual is the continent Ulthuan, the home of the High Elves. Considering its location and beauty, it's obvious that Ulthuan is based on Atlantis.
Warhammer has plenty races, not all of them are in the game.
But looking at the game, one can arrange them like this:
- Elves divide into High Elves, Dark Elves and Wood Elves.
- Men divide into Empire, Bretonnia, Norsca, Kislev and Grand Cathay (last two in Warhammer III)
- Undead divide into Vampire Counts, Vampire Coast and Tomb Kings.
- Chaos, the true evil in the world (yes, there are many evil races, but Chaos is superlative of evil), is divided by the four Chaos Gods Khorne, Tzeentch, Nurgle and Slaanesh. All of them will get their own Faction in Warhammer III. Until now, Chaos is one Faction, called "undivided" Chaos. This undivided Faction will remain next to the other four.
- You talked about animals, so you mean the Beastmen, Lizardmen and Skaven.
- Dwarves are not divided, but there are Chaos Dwarves, a possible candidate for the unannounced last Faction of Warhammer III. Another option could be the Ogre Kingdoms.
- Greenskins are undivided too.
All together make 22 in total, seven of them introduced in Warhammer III.
I could explain all the Races a bit but i don't want to pollute the Thread. So if you want to know something, just ask