WHAT TO CHOOSE

I am a new player got intrested in dd2 so i came across a vedio of dragon dogma online revival and legacy i understood that u can just downlode it for free and play online with friends so first thing is it safe as i am new and second of all do i need to buy dragon dogma dark arisen and give me some recomendation regrading which to choose revival or legacy and what are the difference between them as i am going to play with my friends .
THANK U