Can I mail in my balance due to the IRS without a voucher and my tax forms? I don't have a printer and couldn't print them out.

No, you need to include Form 1040-V if you mail your payment. However, there are other ways to pay your tax bill without writing a check. See below (click the IRS Payment website link):

https://ttlc.intuit.com/replies/3301258

So what happens now...we sent in the check with out a form since there was no indication after filing that we shouldn't send it in, UNTIL 2 days later and it was accepted, well it was too late by then. Do we need to cancel and re-submitt?