I have never noticed a difference between shredded and whole vine. Some people say the shredded vine may oxidize more quickly, but as long as you are buying from a reputable vendor, quality should be great. I never had a problem when I bought shredded from a source I trust--sometimes whole in the colors I want isn't available.
I personally prefer whole vine, just because whole cuttings of vine are amazing to have (I sleep with one under my pillow
), and I really dig the energy of hammering it apart by myself. It's an extra practice of devotion, another way to infuse the brew with intentions. Sometimes, however, living situations make this difficult, so it's just another thing to consider.
Yellow is a very well-rounded experience, and would be an excellent color to start with. Each color is different, so once you get your brewing techniques down, it is quite interesting to branch out and sample other flavors.
Some things will come easy, some will be a test