Welcome to the forum!
I've never had a young puppy either (though I've fostered them) but crate training is a good thing, done properly, and will keep the puppy (who will be into EVERYTHING) safe from harm when you can't watch her, or aren't home.
As for food, I am a bit of a pet food snob, I don't believe in feeding anything made by large corps, or anything that's made in a factory not owned by the owner of the pet food. (canned food is the exception, as I believe only Fromm makes their own canned food)
I will feed Fromm, Horizon, Orijen, Acana, First Mate, The Honest Kitchen, raw, and scraps. My dogs and cats get a variety, as I certainly wouldn't want too eat the same thing day after day, and I also don't think it's all that good for dogs to only eat one kind of food (a good way to develop allergies, and to cause a sensitive digestive system) So my dogs (and my cat) get something different every meal.
Feeding canned food is not bad, like people will tell you, a quality canned is just as good for a dog as a quality dry, so you don't have to be stuck on finding a dry food only. The whole good for teeth thing is a myth, dry food does not make better dental health. the only thing that're good for teeth are bones and brushing (I feed my doxies raw chicken necks, backs and drumsticks once a week or so for dental health)
As for housetraining... be prepared to be patient! Keep it positive, and ignore the accidents. it could take awhile... doxies are notoriously hard to housetrain!