Tell what the following people are going to do tomorrow, by changing the present tense verb to the correct form of the future tense. tú practicas el piano.

Present: Tu practicas el Piano 
Future: Tu vas a practicar el piano

Since you're asking about the future tense, I'm assuming that you need the verb prácticas in future tense. Here are are the ways its conjugated

Yo practicaré
Tú practicarás
El/ella/usd practicará
Nosotros practicaremos
Vosotros practicaréis
Ellos/ellas/usds practicarán
So it would be

Tú practicarás el piano
I hope this is helpful! The endings come after the -ar, and keep in mind this only works for ar verbs.

El artículo más apropiado es el planeta es de nosotros

¿dónde está la siguiente palabra?