Any covid positive patients treated symptomaticaly, Ur baby is having only cold. So need treatment for  cold. Usually infant are obligatory nasal breather , so due to nasal congestion and blocked nose due to secretion child get irritated and noisy breath  So use nasal saline Like Nasoclear 2 to 3 drop in each nose frequently 3 to 4 hourly.

Greetings kindly look for any breathing issues ,if  nasal block use Nasoclear nasal spray 1 drops four times a day