Starting off you will have to make a couple of choices I will focus on several parts of your post first, "digital marketing" , thats a pretty broad scope, you should narrow that down, what kind of digital marketing because there are many types of the digital market place that you can pursue narrow it down and focus on 1 to start that you are interested in , research it get familiar with it , once you have that , it sets the direction of what you focus on next , because that alone makes you no money , you have to apply that, combine or attach that to an action which becomes the engine to creating an income stream , example : I want to sell ebooks you need the source, ebooks , unless you write yourself you will have to get the ebooks you want to sell , then you need a place to sell them , web site , or some kind of platform where you can sell , then you need to promote either your ebooks directly or thru a platform so they reach their target audience and start selling , once you have your first stream flowing and generating money regardless of the amount you build on it scale it up maybe add digital music , ideally you want to create multiple streams of income , but always ensure your first one is working before adding the next , there will be trial and error dont let it discourage you