Hello, Im sure this has been answered before, but anyway, here goes!
When does my Shopify Website “Go Live”?
Do I have to wait until my first payment goes through? Or can it go live sooner per chance??
Also, is there a list of things i need to do before it goes live?
Also, can I leave my page as "https://pixisshop.myshopify.com/" ? And not connect to my domain?
Will this still work as a subdomain? 
Thanks…
Hi there, @velas !
Welcome to the platform and welcome to the Community!
You can have your website go live as soon as you choose a paid plan as well as turning off the password page on your store. For more information about this, feel free to checkout this resource from our Help Center.
We also have this great checklist for you to use as a guide during this set up process.
Your Shopify URL is automatically your main domain. If you do not want to use any other domains on your site, this is more than fine as it not only does it act as your username on the platform but this domain is also included in your Shopify subscription.
Definitely let us know how this works out for you.