I have a g in box 7 of my 1099-R now what do I do to prove I deposited it into my vanguard account

No proof is required to be included with your tax return.

However, you do need to enter the Form 1099-R and answer the follow-up questions.  If the rollover was not to any kind of Roth accounts, answer No to both questions about that.

Please refer to Form 5498 which will show the progress of your money. Keep it for your records.