Learning to ride Fixed gear is just like riding a bicycle.

What the advantages are, or whether it's "better" depends on your environment and goals. If it's hilly where you ride, fixed is not better, unless you want to get stronger climbing, and develop a good spin while descending. If it's flat, 1 gear- the right one- is all you need. If you're not in shape, or don't want to have to work so hard, stick with a single speed, at least.

Fixed is potentially more dangerous, but a brake and foot retention, plus experience, minimize the risk. I know roadies who are intrigued by fixed gears, but apprehensive about riding one. Certainly they're simpler, and I enjoy the smooth, quiet ride. But if a geared bike to too complicated, you probably shouldn't be using a computer, a phone, or driving a car either.