Digital marketing is a broad field that encompasses different aspects, and I don't think you need a bachelors degree to become a digital marketer these days especially if you're going to freelance, but for a full time role I can say a degree might boost your chances, digital marketing is in demand nowadays.
To get started I think you need certifications and there a lot of free certifications for digital marketing on Google learn, all you have to do is make some Google searches and you're good to go, you can also browse job opportunities and see the kind of skills they require and learn them.