Students in our skype English classes from Spain often translate ‘ir/venir andando’ with ‘to go/come walking’. Whilst you will be understood you want to avoid this structure. Please use ‘on foot’. For example, ‘he venido a la clase de inglés andando’ should be ‘I have come to the English class on foot’. Similarly, ‘iré andando’ must be ‘I will go on foot’. Hoping that helps!