How to relieve a two year old cough and stuffy nose? any medicine?

Col.: nit enough information does your child have a fever is he wheezing or is his breathing sound very noisy as this could be bronchiolitis if none of these are present other than runny nose and cough saline nasal washes increased fluid intake can do the trick . If it does not resolve follow up with the pediatrician

May be allergy: This 2 years old cough and stuffy nose might be due to some allergy ,you can try some anti allergic medicine like claritin (loratadine) , it may give you some relief.You should also drink lot of fluids .Your health care provider may examine you and suggests you treatment or may refer you to allergy specialist

Be wise and patient: In perspective a cough and runny nose are very likely to be a minor viral upper respiratory infection (a cold). Danger signs would include high fever (over 101), pulling at the ears, very fast or difficult breathing. No need for meds even over the counter products. Maybe temporarily avoid dairy products which make mucous and more congestion.