“has placed” = the Father loves the Son and because of this love He has given all things to Him.  This shows the dependence of Jesus on the Father.  Even though He was the Logos and the Son of God, Jesus was really and completely human while here on earth.  He had to depend upon God just like everyone else.

“everything” in this context is specifically referring to the gift of life in the Holy Spirit.  When we come to Christ for salvation, it is the same as coming to the Father.