No worries about the questions

That's what forums are for!
The new rulebook, Prime Mk2, includes some of the models for each of the "original" Warmachine factions; Cygnar, Khador, Cryx and the Protectorate of Menoth, as well as a few mercenaries. So you don't get the stats for all the models in just that one book, unfortunately.
But you get all the core rules, and I'm sure that some templates will be included as copy-and-cut in the back of the rulebook, as they were in the first iterations of the core books.
If you buy a Faction Deck, however, you get one (or probably more, in the case of 'jacks and non-character solos) stat cards for every model available to that faction. Each faction (except the Retribution of Scyrah) has a Faction Deck coming; all of them are being released later this month ... on the 20th, I think.
The one drawback of this is that you more or less need to know which faction you want to play before you buy the Faction Decks... but fret not! Privateer Press released a PDF containing all the stat cards for the original four factions and all mercenaries in the game! These aren't the final-final rules, as some minor changes have been made in the printed release, but they're good enough for you to get a good idea of what's available. It seems that with the release of the book, that Privateer (wisely enough) has removed the PDF's from their site ... but they'll still be floating around the net somewhere. Send me a
PM and I can "hook you up"
Privateer Press has changed their usual release strategy temporarily with Mk2. Usually they release _one_ book with new goodies for _all_ the factions, but because Mk2 gives completely new stats for all the previously released models, Privateer is releasing Warhammer-like "army books", which contain Mk2 rules and fluff for all the previously released models. Once all the army books are released, Privateer has said they'll be going back to their usual strategy, so the next "big book" will have new toys for everyone again.
As for die, you need normal
d6's (there are no specialized die in Warmachine or Hordes), so just get some of those. You'll need at least 3, but get another few for some of the more kwazy rolls; I'd suggest getting 5.
But if you're already into Warhammer, you'll probably have plenty lying around
As mentioned, templates will probably be in a copy-and-cut format in the Prime book, but you can get some nifty templates from Privateer themselves, or Gale Force Nine, that go with Warmachine.
There isn't a real "box set" for Warmachine, like there is for the Warhammer games; but there is what is called Battleboxes. These contain a Warcaster and a small selection of warjacks to go with them. These boxes are usually pretty good value for money (at least if you ask me), and you're off to a good start in learning the finesses of the game by getting one of those.
Hordes is actually a stand-alone game, but it uses (almost) the exact same system as Warmachine, so the factions from Hordes and the factions from Warmachine are 100% compatible. You can see it as a four whole new factions for Warmachine, but there are some game-mechanical differences between Warlocks (Hordes) and Warcasters (Warmachine) and Warbeasts (Hordes) and Warjacks (Warmachine). The old Hordes and Warmachine rules (Mk1) were also compatible, but since the Warmachine Mk2 rules came out a long time before the Hordes Mk2 (test) rules, that a lot of Hordes players have had to shelve their Hordes armies for a spell. But with the still ongoing field test, we can finally dust off out beasties and get a-crackin' again!
Sorry for the wall of text, but I hope that it answered your questions properly! Welcome to Warmachine!