It will not matter what order you do that. You can either file this years return and amends last year return, or amends last years return and file this years return. Amended returns do not “catch up” to your original return and replace them; they are processed as two separate returns.
Amended returns have to be printed and filed by mail. It can take the IRS up to 12 weeks or longer to process them. If you are due a larger refund than on your original return, your amended return should only show the difference and you will receive a separate check for it. If you owe money on your amended return, it will show only the new amount owed, you will have to mail a check with the return. Click here for amending instructions: https://ttlc.intuit.com/replies/3288565
How many times can I amend one year's tax return? Thank you!