I wanna paste the initate checkout script to my checkout page. However I don't have a "checkout.liquid" or anything..
Here is an image if templates I have if that helps :P https://i.imgur.com/ZjTOlcF.png
Also I'd rather not put it on the cart page.
checkout.liquid file only visible in shopify plus plan.
If you wants to add script on checkout page then-
1. Chat with shopify support team for enable checkout script.
2. Go to the Settings -> Checkput and add the script in "Additional scripts" section.