Looks like you're getting the hang of it pretty quickly to me! Nice job.
Those pink lines in the 3D view are the surface normals; they show which direction the surface points so you can tell if something is inside-out. You can toggle them on and off by clicking 3D > Normals or by pressing the 'n' key on the keyboard.
For snapping multiple vertices, a good way to do is to use Snap Together by Distance. Move the two tube ends reasonably close together, then highlight the vertices on both sides and click Vertex > Snap Together by Distance. Enter a distance that's greater than the distance between the vertices, but not so large that it will snap all of them together. This will join the two parts without having to click each vertex.
Here's a basic texture tutorial:
http://www.inivis.com/ac3d/tutorials/carbody/index.html
This thread might come in handy too:
http://www.inivis.com/forum/showpost...2&postcount=10