Learn Portuguese (Portugal): Eu mudei-me para Lisboa há um ano.

In Portuguese, a form of the verb haver (to exist / there is) is used to talk about elapsed time. When you say há um ano, you are literally saying "there is a year" since the event happened. This is the standard way to translate the English concept of "ago".

Why is there a -me attached to mudei? Doesn't mudar just mean "to move"?

The verb mudar on its own usually means "to change". When you want to say "to move" (as in relocating to a new home or city), you must use the reflexive form mudar-se (literally, "to change oneself"). Since the subject is Eu (I), the pronoun becomes me, making it mudei-me.

Could I put the pronoun before the verb and say Eu me mudei?

In Portugal, the general rule for basic affirmative sentences is to put the pronoun after the verb, connected by a hyphen (mudei-me). Placing it before the verb is standard in Brazil, but in European Portuguese it is only done if a specific "trigger" word (like a negative word or certain question words) forces the pronoun to the front.

Why do we use para instead of a for "to Lisbon"?