I too have seen my share of owner grooms... but nobody is perfect on their first try. While I think $50 is super cheap for a haircut on a doodle (I charge $90-$100) there is nothing wrong with wanting to do it yourself to save money. If you want you can post pics and I'm sure the groomers will help critique and give you pointers. It would help to also show which clippers you bought and which blades you bought. If you want you can send me pics privately and I can help you out. I can also take pics of dogs as I'm grooming them so that you will have a visual reference.
Don't worry, Callie doesn't know she looks silly (unless you keep pointing and laughing at her) and it is hair, it will grow back.