There are two ways to move or sort the cards in your hand.
1. Manually: By tapping on a card, it is highlighted and thus considered selected. If you keep your finger pressed on the card, you can pull it up a bit and then move it to the desired position. To do this, move your finger to the left or right.
2. Automatically: You can sort the cards automatically in your hand so that the same card values are placed next to each other. To do this, tap on the card icon to the left of your hand cards.