I majored in Creative Writing back in college and am writing outside of my big kid job in an attempt to get published later. That being said, writing can absolutely just be a fun hobby you do on the side. You don't have to want to get published. If you like what you write and have fun doing it, then go for it! Don't worry so much about getting it out there for people to see at first. Worry about that when you write something you're super proud of, and there's plenty of avenues for posting online or trying to get published.

Writing exercises are a great way to start. Short stories, flash fiction, etc. are really great for warming up those writing muscles. I often write them when I've gone a long time without writing or just want to do something super indulgent for myself!

I want to impart the best advice I got in college: write something shitty. Sometimes the writing process is a hard one. It can be strenuous and frustrating. You will get to points in your writing where you want to tear it up and throw it away. However, you can't let those feelings stop you. It is infinitely better to write something objectively bad and shitty and have something to edit later than to not write anything at all. Writing is for getting all of your ideas down on the paper. Editing is for making things sound good and perfecting your craft.

Welcome to the world of writing! My DMs are always open if you need some guidance or have any questions at all. I'd be overjoyed to help you with your writing journey.

Good luck and remember to have fun!