I’m used to holding my breath during curls instead of breathing out on way up and breathing in way down

It feels very unnatural. Is this common beginner mistake? How long till it feels natural?

I was always taught this from playing tennis at a young age so it came naturally when I transitioned into the gym.

Keep doing it. It will eventually feel normal.

I would say only hold your breathe when bracing for heavy lifts 🤷🏽‍♂️