You already have one past tense, the pretérito indefinido, for things that happened and were over: Ayer jugué al fútbol. — Yesterday I played football. Spanish has a second one, the pretérito imperfecto — the past of things that used to happen, again and again, or that went on for a while:

• Cuando era niño, jugaba en la plaza. — When I was a child, I used to play in the square.
• Los domingos, comíamos en casa de la abuela. — On Sundays, we'd eat at Grandma's.
• En aquella época, ella vivía en Sevilla. — At that time, she lived in Seville.

English has three ways of describing a habit like this — I used to play, I would play, or a plain I played — and Spanish uses this one tense for all three.

Three new expressions:

• jugar — to play: games and sports — jugar al fútbol, jugar en la calle.
• montar en bici — to ride a bike (bici is short for bicicleta).
• era — ser in this tense: cuando era niño / niña, when I was a child.