Should I go to a concert alone or is it better to go with a group?

Depends on who's performing and what kind of guy you are. I prefer going solo myself - you listen to the music, no distractions, you can stand wherever's comfortable and leave whenever you get bored. But if it's your favorite band's concert and there are cool people who appreciate them too - it's fun together, and then you've got stuff to talk about afterward. The main thing is that the company doesn't ruin the vibe and doesn't force you to leave early or stay till the end just to be polite.