I meant to reply slightly further to suggest a couple of things too.
The Minigeddon variant is a good way to introduce yourself and others to the rules - it's a smaller sized game (1/3 of the points of the standard game size), on a smaller table, with less objectives and more restricted selection choices.
https://sites.google.com/site/epicarmag ... minigeddonAlso when learning the game Orks vs Imperial Guard are probably the most recommended. Space Marines are a powerful army, but with a but more fiddly special rules and that require more skill to use well (unlike in 40k where they are the go to army for beginners).