YEC is "Young Earth Creationist" and we use that term to distinguish them from the Old Earth Creationists, like Hugh Ross (of Reasons to Believe).
It is quite possible to be a Christian without being a Creationist and, well Creationists often don't seem to be very good Christians - you will probably find that you have been given a lot of misinformation, for one thing. To be honest, if the religious aspect is important to you, I suspect you might get more out of theological discussion rather than scientific.
Young Earth Creationism is thoroughly refuted by the evidence for an old Earth (see RAZD's dating thread which got a bump today)
The main lines of evidence for evolution are :
Taxonomy - the Linnaean hierarchy is a fairly natural outcome of evolution but rather surprising otherwise.
Biogeographic distribution of species - this was the big one for Wallace, who independently came up with much the same theory as Darwin. Things like the unique species found on islands, or the big division of the Lombok line.
The fossil record - the fossil record outright tells us that the species present on Earth has changed over time, and the ordering strongly supports evolution. There are also some really striking examples of transitional fossils. The fossils showing how the mammalian jaw was rearranged is a good example.
In more recent decades genetic evidence has been added to the list, and it still supports evolution.