Hello Glenn,
You can do that easily by adding another #set directive after your first page.
#set page(margin: (top: 1cm))
= Title page
#pagebreak()
#set page(margin: (top: 2.5cm))
= Page 2
On another note, please be careful to follow the guidelines at FAQ - Typst Forum 
. Notably:
- This seems to be a question, so use the Questions category.
- Add any tags, e.g., layout, you think are relevant to the question, and provide a minimal code sample if possible.
Best