Wherever possible, you should make sure that all your web content is visible on the page and not hidden within expanding/contracting boxes.
This makes it easier for users to find what they need, and makes important content or calls-to-action less likely to be missed.
It is not helpful to hide key information from users when all of it might be relevant.
If you think a page might be too long, you can divide your content into child pages, or put feature boxes and headings to good use.