First of call, welcome and congrats to you for taking a first big step. I am so sorry about the loss of your dad (::hugs!:
and it is amazing that you want to get healthier for your daughter.
If you don't know what kind of diet you want to try, Weight Watchers, Ideal Protein, Calorie Counting, Meal Replacement etc,
Take some time and poke around in the different sections here and read up about the diets and see how other users are fairing on them.
This is a great forum and you will have lots of support through out your weightloss journey. Any questions you have, please ask!