Thank you for reaching out to the Community Forums! Congratulations on your new store you are creating. Your store's merchant ID can only be accessed by our live support, as it is your business' unique identifier as well in our system. You can connect with our live support by following this link, signing into your store and searching for the issue in our Help Center: Shopify Help Center - Contact Support.
For setting up your website, we know that can definitely be a process! If you need additional help and are on a short timeline our Expert Marketplace is a great place to get some help! You can review our highly rated experts and get the help you need ASAP - Shopify Expert Marketplace.
If you have any additional questions we can answer for you here, please don't hesitate to let us know.