Learn Portuguese (Portugal): Ela lê uma revista.

The accent tells you two things: which syllable to stress, and how to pronounce the vowel. The circumflex (^) on the e creates a "closed" sound—similar to the a in the English word gate, but shorter and tighter. It also helps distinguish the verb lê (reads) from the pronoun lhe (to him/her) when spoken, and from other words when written.

Since this lesson is about the simple past tense, how do I say "She read a magazine"?

You are currently learning the regular past tense endings for -er verbs, but the verb ler (to read) is irregular! Instead of following the exact regular pattern you are learning, the past tense for "she read" is leu. So the sentence would become Ela leu uma revista.

Does revista always mean "magazine"?

In the context of things you read, yes! The word actually comes from the idea of "reviewing" something, and in some specific contexts it can mean an inspection or a military review. However, in everyday Portuguese, uma revista is just the standard word for a magazine.

How do we know to use uma instead of um before revista?