Hi, is ti possible to create a checkout using “checkoutCreate” and also input the shipping address rather update it later via "checkoutShippingAddressUpdateV2 "?
Yes, as per the checkoutCreate GraphQL docs, the CheckoutCreateInput type also takes a shippingAddress field of type MailingAddressInput.
https://shopify.dev/docs/storefront-api/reference/checkouts/checkoutcreateinput
My recommendation would be to install a GraphQL client and try it out!