Juan se pone el traje negro. Él y su hermano Esteban se ponieron los pantalones y la camisa azul para la boda de su tío.

In this type of exercise it is important to know the basic verbs in Spanish.
It should be noted that since there is no statement, there is no predetermined tense. So I have chosen the present indicative, a very common tense.
Present indicative of verb "ponerse" (to wear);
- Yo me pongo
- Tú te pones
- Usted se pone
- Él se pone
- Ella se pone
- Nosotros/as nos ponemos
- Vosotros/as os ponéis
- Ustedes se ponen
- Ellos/as se ponen