Maelstrom, Wayland, Wargames Workshop, etc. all stock Warmachine. You'd probably be looking at a battlebox for one of the factions to get started, and they come with "quickstart" rules.
At some point you may want to pick up the full Prime MkII rulebook, the faction book (the Warmachine equivalent of a codex) for your chosen force, tokens, templates, and of course more models!
Just a battlebox should be enough to get you started though.
At some point you may want to pick up the full Prime MkII rulebook, the faction book (the Warmachine equivalent of a codex) for your chosen force, tokens, templates, and of course more models!
Just a battlebox should be enough to get you started though.
Figures painted in 2016: 4 
"What this game needs is a panda with a chaingun."
"What this game needs is a panda with a chaingun."