My girlfriend hasn't responded to me for a day after a fight what should I do Text her back or wait for her to text me?

It's often best to give her some space after a fight, as she may need time to process her feelings. You could send a brief, calm message expressing that you care and are open to talking when she's ready. Avoid pushing for a response, as this may increase tension. Ultimately, patience and understanding can help both of you work through the situation.