to charge ahead literally means to move forward quickly or run forward. It implies running or moving with a lot of power or momentum. Your quote uses a figurative sense of this.
I am not sure what a charm offensive is, but I can guess. I think it would be when a person has an intention to "win over" an individual or group by presenting himself as very charming. It does not sound very honest to me to do from a personal viewpoint, but there professions where this is common, such as in Hollywood or professional models.