Tap to focus and wait for sometimes. If still it is not focusing that could be because you are very close to the object. Kindly maintains atleast 10 cm distance to focus well.
Dear Samsung Member,
Greetings from Samsung Customer Support!
Please perform the below mentioned steps to resolve the issue:
* Clear camera lens with a microfiber cloth or a cleaning wipe. Gently remove the fingerprint, dirt, and dust from the camera lens.
* Reset camera settings
Camera > Settings > Reset settings > Reset.
For further assistance, register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
Thank you for writing to Samsung.
Samsung Customer Support