If you’re new to cycling, after getting a bike and a helmet, the next thing I’d recommend is a front and rear light.
Many people ride only in the daytime and think they don’t need lights, but cloudy days, tunnels, and rainy weather all call for them. In cities, a bright rear light can make drivers notice you earlier.
I’m currently using a combo setup from Gaciron — Cetus-1700 front light + Loop-100 rear light — great value for money: https://www.gaciron-shop.com/