Im speaking from experience .
I was Baptised in the holy spirit by God after believing the gospel I was reading.I received it Aug 31,1998 while I was praying in my home .There were no other humans in the house to lay hands on or Baptise me in water.God had done this on his own without assistance .
Mark 16
15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
I was reading the gospel according to Mathew at the time.
You mention you have received the Holy Ghost. Have you been water baptized in the name of Jesus for remission of your sins?
The baptism referenced in both Mark 16:15-16, and Matthew 28:19 is water baptism. This truth is revealed in each of the detailed conversion accounts:
Acts 2:38-39, 42 "Repent, and
be baptized every one of you in the name of Jesus Christ for the remission of sins,
AND ye shall
receive the gift of the Holy Ghost.
For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls."
Acts 8:12-17 (Samaritans-half Jewish-half Gentile)
But when they believed Philip preaching the things concerning the kingdom of God, and
the name of Jesus Christ, they were baptized, both men and women.
Then Simon himself believed also: and when he was baptized, he continued with Philip, and wondered, beholding the miracles and signs which were done.
Now when the apostles which were at Jerusalem heard that Samaria had received the word of God, they sent unto them Peter and John:
Who, when they were come down, prayed for them, that they might receive the Holy Ghost:
(For as yet he was fallen upon none of them: only they were
baptized in the name of the Lord Jesus.)
Then laid they their hands on them, and
they received the Holy Ghost.
Acts 10:43-48 (Gentiles)
43 To him give all the prophets witness, that
through his name whosoever believeth in him
shall receive remission of sins.
While Peter yet spake these words,
the Holy Ghost fell on all them which heard the word.
And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
For they heard them speak with tongues, and magnify God. Then answered Peter,
Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?
And
he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days.
Acts 19:2-6 (Disciples who did not realize they had to water baptized in Jesus name)
He said unto them, Have ye received the Holy Ghost since ye believed? And they said unto him, We have not so much as heard whether there be any Holy Ghost.
And he said unto them, Unto what then were ye baptized? And they said, Unto John's baptism.
Then said Paul, John verily baptized with the baptism of repentance, saying unto the people, that they should believe on him which should come after him, that is, on Christ Jesus.
When they heard this,
they were baptized in the name of the Lord Jesus.
And when Paul had laid his hands upon them, the Holy Ghost came on them; and they spake with tongues, and prophesied.
Acts 22:14-16 (Paul's water baptism)
And he said, The God of our fathers hath chosen thee, that thou shouldest know his will, and see that Just One, and shouldest hear the voice of his mouth.
For thou shalt be his witness unto all men of what thou hast seen and heard.
And now why tarriest thou? arise, and
be baptized, and wash away thy sins, calling on the name of the Lord.