Well the questions you need to answer are the ones that your target audience are asking! You don't get Google Points just for answering questions!
Don't fall into the trap of creating the kind of Frequently Asked Questions page where none of your target audience care about any of the questions! You see this a lot when businesses take a very internal perspective and forget who they're meant to be talking to!
Don't waste your take creating content around questions that nobody is asking!
There's a couple of things to consider here:
1. What are the questions you need to answer on the landing page in order to get visitors to convert or take the next action. (How much does it cost, etc)
2. Then there are broader questions for which you want to try and get a slice of the traffic (eg: where's the best place to hire bikes in alsace etc... )
If you're got access to search console you can look for queries that contain question related words ("how, why, where, when, what etc).
You can also use these in search queries too. For example "inurl:how alsace bike" got me "How long is the Alsace wine route?" and more. Also, do take a look at the pages that appear in the search results for ideas too.
Keep an eye on the related searches displayed in the search results as well.
I have found that it's useful to have a friendly chat with the the business owner/sales people - they can usually (but not always!) give you some insights into the questions that are important to potential customers.
For many topics, the questions that people are are going to be the same as similar topics so taking a look at your direct competitors or site's with similar offerings can help you generate ideas.
If you've got site search set up on the site make sure you're capturing the searches people are doing there, again that can help give you some ideas.
If you've got a chat widget enabled on the site, it's worth seeing if you can get your hands on the transcripts or questions that are being asked there.
You might also consider carrying out a survey, particularly if you've got a good social media following / subscriber list.
Doug.