Advice on buying a new camera?

I'm looking into buying a new camera for personal use. Im not sure what all I need to look for. I've got a 4 year old daughter and will use it alot taking pictures of her, I also like to take trips and take photos of various tourist attractions. Would like to keep it under $500, but would spend more for the right camera. I was told it's all in the lens? So maybe something with interchangeable lenses? Thanks for te help