I recommend a moderately priced electric guitar (NOT the first rock bottom cheapo you can find!) for the beginner, as it is much easier to play. However, I started as a child and didn't have access to an electric for ten years after I started playing, so I can say with certainty it is definitely possible to learn on the acoustic. If you already have access to an acoustic it would be wise to start there and see if it is something you want to pursue before investing five hundred dollars in a starter electric ensemble.
I have had a number of students express an interest in learning on the acoustic, with the idea that since the acoustic is more difficult to play, this will somehow make them a better guitarist faster. I do not agree with this. You will have enough difficulty without deliberately choosing the harder path. If you can afford an electric up front, this will be an advantage. If not, don’t worry about it, just get started.