That depends on you! It's not a good or bad idea. Some people are self motivated and or are introverted, or simply don't have the same schedule as others so riding alone is good; while others need the motivation of a group to keep going and want the interaction of others.

I use to be self motivated but for some reason as I've gotten older (60 now) I've been having more problems motivating myself, so next year I plan on joining club.