how do.you get your child to understand no?

I'm at a complete and utter loss. my daughter is a little over 7 months old. She pulls my hair almost every time I hold her (even when it's up and I almost.always have it up) and bites sometimes during feedings. I tell her no but all she does is smile and laugh. I've tried setting her down. holding her hands. pretending to cry. ignoring it. anything I can think of but she just doesn't get it at all. any advice for this clueless ftm would be greatly appreciated