its not at all hard to prepare oxygen by electrolysis. if the electrodes are properly inserted in galss hood or test tubes and current passed through them, hydrogen and oxygen raises to top, where it gets collected. if a opening is given at top you can safely collect them with out any danger. Hydrogen is twice in volume when compared to oxygem.
Hydrogen by itself is combustible gas, but when its mixed with oxygen and air it becomes explosive.
Yes, pure water is bad conductor of electricity, acid has to be added, but if acid is unsafe add common table salt to it.
The other simple way to make oxygen is to drop 30%or 70% hydrogen peroxide on any silver catlyst. Hydrogen Peroxide immediatelt decomposes into oxygen and water. Its very safe. Same reaction is used in certain hybrid rockets to make oxygen in them.