Hi welcome to HCM... Your loin pain in kidney area could be from viral infection like viral bronchitis as it can lead muscle ache .... Second yes pain could be musculoskeletal... For which analgesic can be taken.... Here you have no fever , blood in urine etc... so chance of kidney infection less... But if pain increasing and fever there USG abdomen done for rule out pyelonephritis ... You have cough ....Rule out its etiology... If it is allergic then antihistaminic drug given.... Chest x ray useful for rule out bronchitis.... In viral infection symptomatic management done ... If cough still there for influenza diagnosis throat swab taken...Then if needed oseltamivir like drug useful... Consult physician for that. Take care