I'd highly recommend trying to reactivate your old character instead of starting fresh.

A lot of the low level content you'll have to do alone. It's not difficult, but it will burn you out quick having to do everything all by yourself. A lot of the stuff you do at low levels is really tedious too - fame building, low level missions, levelcaps, skilling up.

Try reaching out to their customer service and get your old account info if possible.