There’s a big problems with many answers. People will be confused for those answers that cannot convince them. A church has much to do with salvation. The problem is where to find the truth church. The question is where are the true church. Jesus had talking about a remnant church. Where are they in our time? 😐😐 Let the Bible answered your question. Read Revelation 12:1-17. Focus on vers 17. And also 14:6-12. Focus on vers 12.
That’s wrong. Salvation is when God freely gives a spiritually dead person spiritual life (born again). This spiritual life produces faith and repentance towards Jesus Christ.
After salvation you are now enabled to do good by the power of the Holy Spirit who dwells within. Water baptism takes place as an external symbol of your salvation, baptism should most likely happen at the church you are then joining. A church should only accept membership from people who profess the gospel.