What supplements would best help me to lose bodyfat & gain muscle?

It sounds to me like you're going to be just fine. You sound more clued on than most people I know. What I normally do if starting training after a long break is I take a lot of protein. Whey (fast absorbing) after workout is best I reckon, and you would definitely benefit from it. At this stage all I'm trying to do is recover quickly so I can keep pushing hard. Sometimes I will take casein protein (slow absorbing) before bed so that my body has fuel to keep building and recovering through the night. I like taking glutamine as well when I need to recover quickly. At your age I would also reccomend some glucosamine to aid joint and ligament recovery and heath. You're right I would use creatine and NO2 after I've achieved a basic level of fitness and find it harder to push further.