Cuando hablas con una persona que no conoces debes usar "usted".
Yes, I like (answer) too. I don’t like (answer) watching tv. Do You like to play video games?( te gusta jugar con los videojuegos?)
Entiendo is the correct answer because "entender," the original form of the verb, is a stem changer, e--ie, and the "yo" form in present tense ends with -o.