Hi,
1. Then please provide a link to a products listing page with the issue along with screenshots of all the options under the "products options" and the "categories options" tab of the menu item of that page.
2. Regarding the checkout, you want to turn on the user account creation setting in the Joomla user manager options page in order to allow people to register on your website.
That's why you get that message "registration not allowed". Once you activate that option, you'll see you'll be able to register even with the Starter edition of HikaShop.
3. Regarding the "payment not found" error, this comes from either the fact that you didn't configure any payment methods in the menu System>Payment methods or that you configured them in a way that don't allow HikaShop to use them. For example, if you configured a payment method with the Authorize.net payment plugin but that you don't use the USD or the CAD currencies, it's normal that you don't see it as it doesn't support other currencies.