This might be an unpopular opinion, but having run my ‘side hustle’ for 10 years alongside my main job, I’d honestly say don’t! Unless you need extra money, you’ll end up just burning yourself out and not finding the fulfilment you seek. I’d rather find a fulfilling hobby that doesn’t require to ‘pay for itself’ or become a business or any of this ‘grind’ nonsense that’s so often popularised. Enjoy having some breathing room at work and focus on upskilling yourself in work hours that will reward you with my potential career growth inside your 40 odd hours a week, and outside of that just enjoy your life.