Q: Change my store from Venezuela to US

Have you tried this :

Change your iTunes Store country or region - Apple Support

Have you read this :

If you can’t change your iTunes Store country or region - Apple Support

If you did, please tell us what happens exactly when you try to change countries.

If you still live in Venezuela, you can access the iTunes store not only from the US, but from many markets, however, you won't be able to purchase anything from those stores. It has to do with some licensing from the record companies that won't allow such transactions.

There are ways around, but try them at your own risk. You'll have to register on the iTunes store from the country you want to buy, but, here's the tricky part, you can not use your own credit card (since it's based in your country of origin), there are websites that will sell you pre-paid visas from other countries so you can register there and you'll have to provide a real address from that country in order to proceed. One website suggested looking on Google Maps for a McDonalds and use that address. I do not know if this will work or not, but look on Google as to how to buy songs from iTunes from different countries. Again, always be careful when dealing with foreign websites that sells goods.

You are likely to have to enter card details, it's one way of checking that you have a valid billing address in the country. From : Why can’t I select None when I edit my Apple ID payment information? - Apple Support

When you change the country or region of an existing Apple ID, you must provide a payment method and update your billing options. If you want to remove your payment method after you change the country or region, you can change your payment information to None.

If you don't have a card issued by a US bank you could try contacting iTunes Support and see if there is anything that they can/will do : https://www.apple.com/emea/support/itunes/contact.html