I find there are less bad beats in Omaha than Texas Hold'em.
Great starting
hands in Texas Hold’em can be and are frequently run down. With Omaha, if you practice good starting hand strategies and only bet aggressively your nut hands (always apparent at showdown), then you will have more fun IMHO.
I do not think it makes any difference what game you start playing first. The basics are all fairly easy to pick up.
I would try all types of poker, to see what you like and more important, are successful at.
The free rolls are a good place to start and learn. Costs nothing and you could win some money.
poker stars has the Astonomer
freerolls. Most of the major games are catered for (Holdem, Stud, Omaha, Razz, Horse etc.) Players on the last eleven tables qualify for $2000 freerolls on Saturday or Sunday
Full Tilt has very good freerolls as well. They also have freerolls restricted to your country.
Those are the only sites I currently play on, but I’m sure others also have good freerolls.
There are many good posts here on Cardschat and the web in general, re strategies for all types of poker.
Good luck and above all else, have fun.