How do I fix my AGI amount I put in the wrong number and when I did try to e-file it say someone with this number already filed

if you already e-filed and it was accepted (you would have gotten an e-mail confirmation) there is no way to e-file a second return. If the first return contained errors you'll have to wait until it's fully processed and then file an amended return. If someone else already filed using your SSN then there is no way to e-file. In this case since you haven't filed you'll need to mail in your return and include an identity theft affidavit form 14039