"Why did the serpent deceive Eve? How could a serpent talk with a human being?"
It should be noted that the term נָּחָשׁ֙ which is translated as "serpent" can also be rendered as "shining one". In the ancient near east that was commonly a term for "a divine being". Going with that rendition:
The Shining One (SO) would have been one of God's angels. At this point in the narrative, God is described as walking in the Garden:
And they heard the sound of YHWH-Elohim walking in the garden in the
cool of the day
That God here is plainly in physical form -- He made sound when walking -- suggests that at least some of His heavenly servants could also come into the Garden in physical form; both had spiritual forms in heaven but took physical form on Earth. So this SO is one of God's creatures with whom Adam and Eve were presumably familiar, since its appearance is not pointed to as having been a surprise. That means this was a being whom Eve knew already and (also presumably) would have trusted as one of God's servants.
We learn elsewhere in the scriptures that this is indeed not just any divine being, this is the top divine being, whom we might describe as "head Prince of the Angels". The SO is accustomed to being God's "number one", His "executive assistant", so to speak. Then here in the Garden he is faced with something new that God has done, making physical beings -- and not just physical beings, but physical beings whom God has appointed His representatives on the Earth. So why did the SO deceive Eve? Well, jealousy is a good guess: he saw God spending time with them in the Garden, and how they (presumably) adored God, and he saw it as cutting in on his special relationship with God.
We know from Isaiah 14 that the SO declared
"I will make myself like the Most High"
which suggests that he was jealous enough that he wanted to cut in on this and get the newcomers loyal to himself -- and that required disrupting their loyalty to God. This is the point where the SO becomes "the father of lies" as he chooses to twist just a little what God had said and thus persuade these humans into in essence giving their loyalty to him.
"How could a serpent talk with a human being?"
Because the SO may not have been a serpent at all, given the other possible meaning for the word used. But if he did take the form of a serpent, as a heavenly being -- what we would call an angel -- making that form able to talk wouldn't have been difficult.