Find a day job where writing is a key component. As others have said, you may need to support yourself as you work on your novels. But while doing that, it would be ideal to still be honing your craft. There are freelance opportunities, or writing content for marketing at a large company.
Conversely, you can find a job that pays the bills but is not a mental distraction if you want to make novel writing your main focus. But be prepared to be a "starving artist" if you aren't looking to get promotions and more responsibility that would distract you from your writing.
Either way, dedicate yourself to finding the time to keep at it.
In short, be realistic about life as a novelist, but don't lose heart.
I'd recommend using the internet to your advantage and learning as much as you can outside of class to help propel you while you take your courses.
Be ready for a ton of feedback that you might not enjoy, be ready to write multiple novels before you find the one that is just right, and don't throw away any of your works because you never know when they might resurface to have a better future.
Read Steven King’s ‘On Writing ‘ and then ‘Nobody Wants To Read Your S**t’ by Steven Pressfield. Both brilliant. Work everyday at it. Don’t give up. LEARN THE CRAFT. These books will help you to do so. Harness the desire while you’re young, it doesn’t necessarily get easier as you get older. Huge amounts of successful artists got rejected many times - they persevered. Persevere.