Shopify Support will need to add Carrier Calculated Shipping to your store. You’re able to contact them through live chat, email, or callback via the Shopify Help Center. This video clip shows you how to access the chat and email option. If you would prefer to speak with someone over the phone, please log in to your store when prompted to view the callback option. It’s good to note that callbacks are only available when capacity allows, so for the fastest support, I do recommend selecting the chat option.
How’s your store coming along? If you’d like to drop your store password in this thread I’d be more than happy to provide you with some feedback. I also recommend checking out the Shopify Store Launch Checklist. It’s an awesome resource to have on hand to make sure you have everything covered before your store goes live.