No.

Jesus says that if he testifies about himself, his testimony is not true. And that if he glorifies himself, his glory means nothing. His enemies agree: If he appears as his own witness, his testimony is not valid.

(Jesus tries to get around this by claiming that his father is also testifying about him. He thinks this satisfies the requirement of two witnesses. But even if it was valid to merely testify that someone is testifying about you, rather than having that person actually appear and testify, that still wouldn’t work. Because Jesus insists that he and his father are one. So either Jesus is a liar, or there’s still only one witness. And we’ve already established that his testimony is not valid, so even if there was another witness, that still wouldn’t be enough.)

Yes.

Jesus also says that even if he testifies on his own behalf, his testimony is valid. And his enemies agree: Once they’ve heard his claims from his own lips, they don’t need any more testimony.