Do I need a website or a funnel, and can I have several funnels on one domain?
A funnel is part of a website project. When you open a website project you see its pages and its funnels, and each funnel's pages appear inside that funnel, grouped on the left side. A funnel is a collection of pages, and you can have as many funnels as you want on one domain or website project, for example for different promos, offers or niches.
If you are only offering a straight trial, a landing page with a signup form is probably enough. If you want more, such as upsell pages, build it in the funnel builder, which adds funnel stats and reporting, comparing landing pages, automations, Visitor ID to identify visitors who do not finish, and abandoned cart emails.
You can create a funnel directly inside the website builder or use the visual funnel builder in the click tracking system. Funnels and sites can both be included in a snapshot.