Good question! We can use "used to" and "would" to describe things we did in the past, but there is a difference: We only use 'would' to describe actions or situations that were repeated again and again and again. We use 'used to' for any extended action or situation in the past.

Great question! When talking about past habits, they mean exactly the same thng. The difference is that, in this context, "would" can only be used to talk about actions, not states. (If you use "would" with a stative verb, it will be understood as the conditional, not as a past habit.) Also, it's typical not to use "would" to talk about past habits at the beginning of your story, because we need to establish the time as past using a tense which is obviously past (like simple past, past continuous, "used to"), or to mention the time, eg: "Five years ago" "Last May" "When I was in kindergarten."