The words "my Lord" in John 20:1213 and Luke 1:43 are similar to Psalm 110:1 ASV Jehovah saith unto "my Lord" adoni, Sit thou at my right hand, Until I make thine enemies thy footstool. The form l’adoni (to my lord) is never used elsewhere in the Old Testament as referring to YHWH. Adoni always refer to a human master or ruler.
Jesus is addressed as “Lord” in the four Gospels, most often in Luke and John. In the first century C.E., the title was one of respect and courtesy, equivalent to “Sir.” (John 12:21; 20:15, Kingdom Interlinear) In Mark’s Gospel the term “Teacher,” or Rab·boʹni, is used more frequently in addressing Jesus. (Compare Mark 10:51 with Luke 18:41.) Even Saul’s question on the road to Damascus, “Who are you, Lord?” had this same general sense of polite inquiry. (Acts 9:5) But as Jesus’ followers came to know their Master, it is apparent that their use of the title “Lord” expressed much more than simple respect.
Following his death and resurrection but before his ascension to heaven, Jesus appeared to his disciples and made this startling announcement: “All authority has been given me in heaven and on the earth.” (Matthew 28:18) Then, on the day of Pentecost, under the influence of the poured-out holy spirit, Peter referred to Psalm 110:1 and said: “Therefore let all the house of Israel know for a certainty that God made him both Lord and Christ, this Jesus whom you impaled.” NWT(Acts 2:34-36)
To the question in one of your comments " Is Mary Magdalene referring to Jesus as God? Or? .
If Mary Magdalene referred to Jesus as God, then that would mean there will be two Gods. If, as Jesus plainly stated that there's only one true God, John 17:3 then one of these two Gods is not the only true God. Consider John 20:17 ASV, (Jesus saith to her, Touch me not; for I am not yet ascended unto the Father: but go unto my brethren, and say to them, I ascend unto my Father and your Father, and my God and your God.) and John 17:3 ASV (And this is life eternal, that they should know thee the only true God, and him whom thou didst send, even Jesus Christ.,) if our understanding of Jesus is that he is God, how can God worship and pray to another God?
The idea that Jesus is the only true God, Creator and Sovereign Lord is not found in the scriptures. Consider Jesus unequivocal and plain statements in Matthew 19:4 Jesus Christ recognized God, not himself, as the One who created humans, making them male and female. (Mt 19:4; Mr 10:6). Based on Jesus' plain and unequivocal statementstatements, the Father is the only true God and Creator, not himself.