while this game is a Massively Multiplayer Online (gee, who would have guessed that's what MMO stood for :-P ), it can be played (and I have done it many times) solo. I would recommend, however, that, if your play time allows for it, get into a group every now and then. my friend, who also plays EQ2, never really started getting into groups until after he was level 40 (close to 50 if not higher) and since he didn't really know how to interact in a group dynamic, he had a major learning curve to overcome.
But it all depends on your playstyle. if you prefer to solo, then by all means, solo to your hearts content. if you want to group all the time, you can do that as well. if you want to do nothing but sit infront of a crafting station and do that all the time you are logged on, you can do that as well (though I would recommend either going out to harvest at least somewhat while you are still low level, or level up an adventuring toon who will also do your harvesting, as that can get really expensive really fast). This game caters to whatever you feel like doing. heck you could sit in your house (well, kneel, since EQ2 doesn't really allow "sitting" like some other games) and do nothing but chat in the world channels if that's all you cared about doing that day (seen it done before).
so, the real question becomes, what do you feel like doing in Norrath today?