hello first and welcome to HD community.
To play Hell Dorado, you need a 30x30 inches gaming table, divided in nine areas of 10x10 inches, determining control areas for scenarios usually.
you play a company composed of 200 points of models, wich means between 8 and 12 minis on the table. 200 points is the standard company size.
it's a skirmish game, so you play games during 30 min - 1 hour maximum for a standard 200pts game.
the game uses a system of terraformation, meaning you may use any types of terrains (the book is really full of example and special rules for each terrain types/modules), but you place a maximum of one terrain piece by control area (9 total).
you may use any type of gaming table, the terraformation sequence is not needed to play a game, but adds a lot of fun and stategy.
to start the game, you will find army boxes containing a 200 points army with leader and troops needed to play your first games.
reinforcment boxes, containing one or two characters, will be released two month by two month to complete in a first time all troops presented in the rule book.
hope that help in your future choices.
ps : hit by mEdwards, but some informations are completing each other... thanks