Learn Spanish (Spain): La película empieza ahora.

Empieza comes from the verb empezar (to begin). It is a stem-changing verb, which means the e in the root of the word changes to ie when we conjugate it for most subjects (like I, you, and he/she/it). Because la película counts as an "it" (third-person singular), we use the ie change to get empieza.

Is the z in empieza pronounced like an English "z"?

Not in Spain! In Spanish from Spain, the letter z is pronounced with a soft "th" sound, just like the "th" in the English word "think". So, empieza sounds roughly like "em-pyeh-tha".

Why does película have a written accent mark?

The accent mark shows you exactly where to put the strongest stress when you say the word out loud. By default, Spanish words ending in a vowel stress the second-to-last syllable. The written accent on película overrides that rule, telling you to stress the lí instead of the cu: pe-LÍ-cu-la.

Can I use empieza to say a person is starting something, or is it just for events?

You can use it for both! Just like in English, an event can begin (la película empieza), and a person can begin something too, like ella empieza a estudiar (she starts to study).