What to say and do if you commit a sin

مَا مِن عَبدٍ يُذنِبُ ذَنباً فَيُحسِنُ الطُّهُورَ، ثُمَّ يَقُومُ فَيُصَلِّي رَكعَتَينِ، ثُمَّ يَستَغفِرُ اللَّهَ إِلاَّ غَفَرَ اللَّهُ لَهُ

English meaning

Any servant who commits a sin and as a result, performs ablution, prays two units of prayer (i.e. two rakAAas) and then seeks Allah’s forgiveness, Allah would forgive him.