There has historically been differences of opinion among Apostolics/Pentecostals/Charismatics as to whether speaking with tongues is the (one and only) "initial physical evidence" of the Holy Ghost Baptism.
Some believe that prophecy could be an evidence. This is based on
Acts 19:1-7 where it says they spoke with tongues and prophesied. Some teach that all of them did both --spoke with tongues and prophesied. Some teach that some of them spoke with tongues and others prophesied.
I preached in an Apostolic church where the pastor taught that speaking with tongues was one of the signs that followed believers. In other words, receive the Spirit of God now and some day some where in the future you will speak with tongues. This was based on
Mark 16:17-20
The "official" doctrine of the AVC (Association of Vineyard Churches) is that when a person repents and commits to Jesus and the Holy Spirit comes into his heart that is the Holy Ghost Baptism. Afterward there are fillings or empowerings of the Spirit and speaking with tongues and/or other gifts may happen as a result of those experiences.