Am I permitted to eat
a meal (dinner)right before I light the Menorah or should I wait and light first then eat
It is forbidden to begin eating a meal during the half hour before candle lighting time (nightfall for those who light at tzeis hakochavim).
It is even forbidden to begin a light meal, lest one get caught up in eating and forget to light the Chanukah candles. It is likewise forbidden to drink alcoholic beverages during this period of time. However, it is permitted to eat fruits and vegetables.
However, it is permitted to eat if one asks a friend to remind him to light the Chanukah candles at the proper time.
See Mishnah Berurah 672:10; Shaarei Tziyun and Piskei Teshuvos.