For cough and cold of 1 day duration, it is most likely a viral infection, which usually improves on its own in 3–5 days.
Regarding the medicines:
Welminic LS syrup is usually given 2–3 times a day (not once daily). Please confirm with your doctor, but commonly 2.5 ml twice daily is used depending on age/weight.
Levocetirizine syrup is correctly given once daily (usually at night).
Important points:
Avoid giving multiple cough/cold syrups together (like Alex Junior + Welminic) — stick to one prescription.
Monocef (antibiotic) is usually not needed for simple viral cold unless bacterial infection is suspected.
Otrivin nasal drops can be used for blocked nose for maximum 3–5 days only.
Next Steps
Supportive care (most important):
Saline nasal drops frequently
Steam inhalation (if age appropriate)
Adequate fluids and feeding
Paracetamol if fever
Health Tips
When to revisit doctor:
Fever > 3 days
Fast breathing / chest indrawing
Poor feeding or lethargy
Persistent cough > 5–7 days
you can consult me on practo if further concerns