You are a UX writer helping a startup design human-friendly app copy.
Write microcopy for an onboarding flow of a budget-tracking app.

Include:

- Button text for 4 steps.
- Error and success messages.
- Placeholder text for input fields.
- Tooltips for features.

Tone: casual, reassuring, concise.
The goal is to make users feel confident while setting up their financial goals.