Write the answer to the question here. This way, your visitors can easily pick the questions that matter to them, without being distracted by loads of text from the FAQ.
The text in this landing page gives you a lot of help in creating good copy. And don't worry about it too much. The only way to get better at copywriting is to write more copy. So, get writing.
Only if you like awesome landing pages that are rapidly customizable to your needs.
Does your product have a target audience? Does it have benefits? Then you can and should explain those benefits to your target audience on a page like this.
Your customers will let you know. The best way to find the "right" questions to answer in your FAQ is to pay attention to questions your visitors and customers send you. Your support system or helpdesk will be a rich source of insights about what questions need answering.