It is not a sin to buy or drink alcohol.
Paul advised Timothy:
1 Timothy 5:23 Drink no longer water, but use a little wine for thy stomach’s sake and thine often infirmities.
Jesus turned water into wine at the marriage feast in Cana.
John 2:1 And the third day there was a marriage in Cana of Galilee; and the mother of Jesus was there: 2 And both Jesus was called, and his disciples, to the marriage. 3 And when they wanted wine, the mother of Jesus saith unto him, They have no wine. 4 Jesus saith unto her, Woman, what have I to do with thee? mine hour is not yet come. 5 His mother saith unto the servants, Whatsoever he saith unto you, do it. 6 And there were set there six waterpots of stone, after the manner of the purifying of the Jews, containing two or three firkins apiece. 7 Jesus saith unto them, Fill the waterpots with water. And they filled them up to the brim. 8 And he saith unto them, Draw out now, and bear unto the governor of the feast. And they bare it. 9 When the ruler of the feast had tasted the water that was made wine, and knew not whence it was: (but the servants which drew the water knew;) the governor of the feast called the bridegroom, 10 And saith unto him, Every man at the beginning doth set forth good wine; and when men have well drunk, then that which is worse: but thou hast kept the good wine until now.
Baptised believers are commanded to share bread and wine in remembrance of Jesus’ sacrifice.
1 Corinthians 11:23 For I have received of the Lord that which also I delivered unto you, That the Lord Jesus the same night in which he was betrayed took bread: 24 And when he had given thanks, he brake it, and said, Take, eat: this is my body, which is broken for you: this do in remembrance of me. 25 After the same manner also he took the cup (of wine), when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me. 26 For as often as ye eat this bread, and drink this cup, ye do shew the Lord’s death till he come.
However, it is foolish to drink alcohol to excess, because that often leads to sin.
Romans 13:13 Let us walk honestly, as in the day; not in rioting and drunkenness, not in chambering and wantonness, not in strife and envying.
1 Corinthians 6:10 Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God.
Ephesians 5:18 And be not drunk with wine, wherein is excess; but be filled with the Spirit;
I hope you find this helpful.