Knowing how to draw realistically is an invaluable tool for any artist, and I massively encourage you to learn, but once you've got it sussed it out that doesn't mean you have to enforce realism on everything you create in future--- far from it! Learning how to draw realistically will only emphasise your unique style, and give it a sense of familiarity we can all recognise, making it easier for us as readers to see what you're trying to achieve.
If you want to start somewhere, try simply learning how to deconstruct the things around you and understand how they are put together. Learn how shapes interact with each other, as well as how things look from different angles and how they respond when pushed or pulled or bent. I draw a lot of hands in my stuff, so I had to learn the shape of each joint of the finger, the thumb and palm-- how each one look upside down, from above or below, and how they sit relative to each other. I had to recognise that fingers aren't sticks or squares, that they fit so well together as to hold water, and apply that knowledge to the skin covering bone.
Use the materials you have in front of you. Recognise that you are trying to figure out how they work-- tell yourself what you are seeing. Learning to draw is an active process and being able to drawing realistically when it is necessary is just another string to your bow. Plus, the better you can project what's in your head, the happier you will be. So do what makes you happy, and remember that how you use these tools is your choice. There are no rules. Just have fun and enjoy yourself.
