1. Cuando era pequena, era rubia, pero ahora mi pelo ya no es rubio.
This sentence means - When I was a little girl, I was blonde, but my hair is not blonde anymore. As you can see, I used the verb SER in the imperfect tense (ERA). Ser is an irregular verb, which means that its conjugations have to be learned by heart - era, eras, era, eramos, erais, eran.
2. Yo amaba jugar con mis amigos y amigas, y yo iba a sus casas para jugar con ellos.
This sentence means - I loved playing with my friends, and I went to their house to play with them. As you can see, I used the verbs AMAR and IR in the imperfect tense (AMABA and IBA) which is used to describe events in the past.