You'll probably enjoy Frenchies, but I'd give Benoit a miss. Alain Ducasse made a mess of this once wonderful bistro, and for the same money, I'd go to Josephine Chez Dumonet or Chez Georges (rue de Mail) or A la Biche au Bois, or maybe Auberge Pyrenees Cevennes.
I actually think Benoit is great, however maybe not fot an 18 year old. Frenchie may be OK. But it isn't a great people watching place. Try Le Chateaubriand not only very interesting (and challenging) food, but also very stylish with lots to look at - the waiters will appeal.