I think lots of us would agree that the first priority is to read one or two Gospels. If you’re going to become a Christian, you need to know what Christ was about. I’d suggest Luke and John. Basically Matthew, Mark and Luke have a lot of similarities, but John takes a different approach.
I’d also suggest that you get involved in a church. Jesus dealt with a group of disciples, and he said his goal was to establish a kingdom. Many of his teachings are really meant to be lived in community with others.
But that brings up the immediate problem. There are lots of kinds of church. Roughly, the likely options in the UK are Catholic, conservative Protestant and liberal Protestant. The Church of England tries to combine these, in a sense.
There’s a major difference among Christians in how we approach the Bible. Everyone agrees that we follow Jesus. For traditional Christians that means that they accept what his followers accepted, including creation of the earth in 7 days, and traditional approaches to women and to sex. More liberal Christians think we’re not locked into the culture of the Biblical authors, but that Jesus can be Lord of people living in a modern culture.
Again, speaking approximately, conservative Protestants believe it’s important to believe all aspects of the Bible. There are intermediate positions, but a real conservative thinks the earth was made in 7 days, that women shouldn’t be leaders, and that it’s critical for the Church to oppose acceptance of gays. Liberal Christians want to put Jesus’ teachings into practice, but think we can believe modern scientific views, accept women as leaders, and accept gays and other sexual minorities.
Catholics are in the middle. Generally in the UK they agree with liberal Protestants on the things I have described, but because the Catholic Church is international, they are bound by its policies to reject women as priests and to consider homosexual sex as prohibited (though privately, a majority hold the liberal views).
Aside from these basic differences, there are stylistic differences in worship, with conservative Protestants tending towards lively, informal services, Catholics to traditional, formal services. (Please don't think the contrast implies that Catholic services are boring. They can be very meaningful. They're just different.) Liberal Protestants tend to have a more academic orientation. (The Church of England has quite a variety. Beliefs of different congregations range from conservative to liberal. While their worship services typically are similar to Catholic ones, some congregations are more informal.)
Normally new Christians have become Christian because of the influence of friends. They often start with their friends’ congregation. It sounds like this isn’t the case for you. That puts you into an unusual position of having to find Christian friends. In the UK, I’d probably start with the Church of England. But everyone posting here will recommend their own church, sometimes in very strong terms. FYI, I’m a Presbyterian. In the US that’s a liberal Protestant group. I’m not sure whether that’s true of Presbyterians in your area.
