Hey there. Just a warning, I wouldn’t consider a significant number of people in this sub to be true marketers. A lot of the “marketers” here will probably advise you to learn some combination of content writing, SEO, AdWords, influencer marketing, social media ads, Google Analytics and possibly web design. These are nothing more than channels and tools to help tell customers about your product (besides Google Analytics). Great tools and channels to study but it’s not what marketing is about.
Marketing is a conversation between you and your customer. You’re asking them questions about their problems, needs or desires. You learn who they are. You empathise with them and as a result of your findings, you craft a solution (the product or service) for their problem or needs. Then using various channels of communication, you will let your customer know that you have a solution and can provide value to them. It sounds like this process may be of interest to you considering your studies.
That’s where marketing begins and it goes on to figuring out how to differentiate and position your product against competitors. You learn how to segment your audience, target audiences via various communication channels, price your products and figure out how to get the product or service to your customer in the most convenient and cost effective way.
I recommend this course from Coursera that will give you a really good start to the fundamentals. It goes through market research, consumer behaviour, product positioning, and the Marketing Mix. Coursera are courses taught by real universities and are usually very high quality. You may go through all of the material and learn it for free but if you want to take the tests and do the assignments it will cost a few hundred dollars. This course in particular, will teach you most of the important stuff from a bachelors degree in marketing without needing to study full time for several years. The course will still take some time to complete but it will give you a real solid foundation.
If that course is a bit too long then I suggest this one. It’s nowhere near as in-depth but it will give you some of the fundamentals. It is taught by Wharton and high quality.
From there, No doubt, other people here will point you in the way of great digital marketing courses to supplement this.