Generally, if the products are legal in areas where you are selling from and to, it shouldn't pose an issue with selling on Shopify. However, some items are considered high risk for Shopify Payments thus you may not use certain gateways for payment processing. It really depends on what product exactly from the smoke shop category you plan on selling.
I recommend you to email directly to Shopify's Merchant support.
Contact page link: https://help.shopify.com/en/questions#/contact/email