First, what's the BnB?
Second, what hits do you usually get in matches? Figure out what those are, then learn combos based on what hits you get. Then learn BnBs off of other moves, when you learn how to get those hits.
Third, you're not going to get huge combos off of the majority of Noel's normals. Her A moves are relatively fast, but they prorate badly. You want to pressure with Noel's normals and put your opponent into a position where they're going to guess wrong. You want to aim for getting her 6B or her 3C, both of which lead into very damaging combos, but are stupidly unsafe to throw out. 5A is one of the fastest moves in the game, so learn some pressure strings with that. 2A is really easy to tick-throw, and you can probably get at least 2.5k off of that.
Or hit them with 5D.
/noel is all stupid gimmicks