Green Car/First Class

Hi,
I'm planning to buy the first class ticket, it is equivalent to the Green car ticket right? I am quite confuse. Is it a must to do a seat reservation? Im planning to go from tokyo to Fuji to kyoto, will I be able to maximize the usage of my JR pass 1st class or I can just buy from there? and lastly which side has better scenery by train : 1. from Tokyo to Kawaguchiko
2. kawaguchiko to Kyoto
3. Kyoto to Tokyo

Appreciate your help. Thanks