Does John 17:3 prove Jesus is not God? Why does the bible call the Father "God" and Jesus "Lord"?

Is Jesus Christ a lesser deity? Texts which say Jesus is God and also LORD in the OT applied to Jesus http://wit.irr.org/jesus-christ-lesser-deity

The Divine name replaced by Lord in the Septuagint https://www.tetragrammaton.org/divname.html#chapter2

For a discussion on LORD and how it is applied to Jesus see the book "Putting Jesus in his Place, The Case for the Deity of Christ" by Robert M Bowman Jr, J Ed Komoszewski, page 159.