The verb nadar, which means 'to swim' in Portuguese and in Spanish, is intransitive. So it doesn't take a direct object. In the phrase of the above question, 'te nada' appears to be an example of the...
It means ' You don't like anything', so presumably you'd reply: 'No; me gusta....'(No; I like....), adding what you like. Unless you DON'T like anything, when you perhaps reply: 'Tienes razon. No me...