What kinds of fields can I create with Fields builder?
You can create the following types of the fields: text, number, price, area, file, select (drop-down), text area, date, email, URL, tel.
Almost every field can be searchable and required or not.
How do they look like on frontend?
New fields added via Fields builder look like all other default fields in the plugin. To systematize them, you can create also sections and assign specific fields in appropriate sections:
In screenshot below you can see Documents, Exterior features and Floorplans as sections with their custom fields. You can reorder both sections and fields, edit or remove them. Please find here detailed documentation how to use them.