Slipping the first stitch or not is a matter of personal preference. I don't do it and I know there are others here who don't. In the video Demo of a Small Project, Amy talks about slipping the first stitch and how to do it. If you work a pattern that wants you to slip the last stitch, or if slipping the first stitch is important to the pattern, there will most likely be an explanation as to whether to slip as if to knit or slip as if to purl; or with the yarn in front or in back.
You're really enthused, and that's great. What needles you will end up wanting to use will depend on your own experience. www.ravelry.com
is free to join and will give you access to lots of free scarf patterns. You can look for easy/beginner patterns and many are free.