Newbie question about double/triple matches

Hi, I'm new here and stuff. Not extremely experienced with Risk, although I did win my third game.
Anyway, I'm a bit confused with double/triple games. Do we get continent bonuses if we share a continent? Or should we agree which one of us gets the continent, then have one of us fortify elsewhere and the other attack? It doesn't say in the rules, and I can't find a thread about stuff like this.

Anyway, I'm a bit confused with double/triple games. Do we get continent bonuses if we share a continent? Or should we agree which one of us gets the continent, then have one of us fortify elsewhere and the other attack? It doesn't say in the rules, and I can't find a thread about stuff like this.