This app was mentioned in 3 comments, with an average of 2.67 upvotes
I really like Cross DJ, i've been using it to teach myself -- can search/import tracks directly from soundcloud which is really nice
https://play.google.com/store/apps/details?id=com.mixvibes.crossdjfree
Not gonna get very far without doing at least a little of your own research.
https://play.google.com/store/apps/details?id=com.mixvibes.crossdjfree&hl=en_US