For me, “receiving the Holy Spirit” is what happens at Baptism, when we receive the faith, the pearl of great price, to start living in Truth (who is Jesus) and communion with God.
“Being filled with the Holy Spirit” would, in the normal course, be the gradual and progressive flowering of the Gifts of the Holy Spirit in our lives, usually the fruit of many “conversions”, large and small, in our journey of sanctification.
One sure sign of being “filled with the Holy Spirit”, for me, is a growing zeal to share the Good News with others - as opposed to just treasuring it ourselves.
That is why we pray, “Come Holy Spirit and FILL the hearts of your faithful, and enkindle in them the fire of your love.” (Note, we are already “faithful” to the Spirit, but we’re asking for more - to be filled with a fiery love).
That’s the fire that makes us love others enough to go to great lengths to bring them too to an experience of God’s love and goodness. To help bring about God’s Kingdom on earth.
And that’s exactly what the Apostles began to do after Pentecost (for them the “filling” was instantaneous), with many of them eventually giving their very lives to the mission.