Hi @Kimber Johnson, Thanks for getting in touch with us.
If you check our documentation on Rental Product Types (https://multivendorx.com/docs/knowledgebase/rental-product/), it has clearly mentioned that you need WooCommerce Rental plugin (https//codecanyon.net/item/rnb-woocommerce-rental-booking-system) in order to let vendor add rental products.
In Fact you can get the same information from module page itself : https://prnt.sc/K9Lcv97yfJJ4
Once you have this Rental plugin, you can start letting your vendor add rental product types.
Also, please note that all the settings related to booking, calendars, and other features related to rental products are provided by the rental plugin itself. Our plugin simply enables vendors to access these features of the rental plugin from their dashboard as well.
Let us know if you need any further assistance.