Learn Italian: Non studio perché sono pigro. - I do not study because I am lazy.

In Italian, subject pronouns like io (I) are usually dropped because the verb endings already tell you who is doing the action. Studio and sono can only refer to the first person. You only add io if you need special emphasis or to avoid confusion.

Does perché mean 'because' or 'why'?

It means both! In Italian, perché is used for asking questions (why) and also for giving reasons (because). You can tell which one it is by the context. Here, it connects two statements to give a reason, so it means 'because'.

Why does perché have an accent mark on the final 'e'?

The accent mark tells you to put the vocal stress on that last syllable when speaking. Without it, the default Italian pronunciation rule would make you stress the second-to-last syllable. The written accent is mandatory for words that end with a stressed vowel.

If a woman were saying this, would the sentence change?

Yes. Pigro (lazy) is an adjective describing the speaker. If the speaker is female, the ending must change to match her gender, so she would say Non studio perché sono pigra.