importing order history

hello,
i have a store in woo for which i want to transfer only order to my shopify store which is already live. i have setup everything but i am getting error like the product doesn’t exist in shopify, though this is true for some products but the same error it is giving for order which have product imported in shopify. but after processing around 1000 items it ended up giving 301 error. how can i get this done. also as the store on shopify is life will it create problem moving orders this way?