You can use a free parking filter. Enter the name of the area you want to search, the dates and the number of guests. Click the settings icon and scroll down to amenities. Select Free Parking.
The search results will only show the listings of hosts who ticked free parking as an amenity.
Good question! Check all listings closely for mentions of parking, and as @Shelley159 mentioned, use parking filters. I am a firm believer in communicating with hosts and guests, so use the contact host option to ask and make an inquiry about parking and another amenities that are important to you.