A bigger plane is easier to keep oriented in the air. If you get the right plane a smaller plane will not fly out of sight any faster than a larger one. A park flyer or slowflyer, will be flyable with in a school yard without a problem. These are electric models. an anything of this size I would go electric.
If you wish for glow powered I would urge you to get a trainer. The smallest I would go would be around 50" Such as the Carl Goldber Eaglet. Anything smaller than this will have to be flown on near zero wind days. Smaller = Lighter = more affeced by wind.