To fully experience the Beatific Vision (i.e., see God face-to-face in heaven), we must be in heaven. There is the possibility that it can be immediately at death for those who die without any stain of sin on their soul, but most of the saved will likely need some cleansing in purgatory. Whether or not we can in some way see Jesus after death and before heaven, is something I don’t know if the Church has determined. Because of the Incarnation, God the Son can be visible to sinful man, so it is possible that we might in some way see him before entrance into heaven, but we may not know for sure this side of eternity.
