learning mobile app development

hi I have a question. i am complete beginner when it comes to mobile app development. The problem like a lot of things is when u google it you find what i would say is too much info so you don’t know where to start. If I’m going to get into this field I would like to at least be able to gain employment or to make money in it some how. I know u have apps or i phones and android. Not sure as a person trying to learn if I,m suppose to just pick one or the other. Personally id like to develop apps that work on both .So many different sites say different things on how to learn that I’m confused. Any advice would be greatly appreciated.