One of the things that we sometimes forget about is that Jesus is God and one of the attributes of God is omnipotence, (the power to do anything). As such, God is beyond the bounds of space, time and (most especially) our capacity to completely understand just how powerful He really is.
Jesus therefore can be everywhere (omnipresence) and anywhere specifically and still not be at all diminished by that.
This probably does not make sense, because even though I am explaining it…I cannot tell you how it is possible, aside from quoting you these verses from Jesus’ own lips.
Matthew 19:26 And Jesus beholding, said to them: With men this is impossible: but with God all things are possible.
Mark 9:22 And Jesus saith to him: If thou canst believe, all things are possible to him that believeth.
Mark 10:27 And Jesus looking on them, saith: With men it is impossible; but not with God: for all things are possible with God
Luke 18:27 He said to them: The things that are impossible with men, are possible with God.