I am not sure about age, but it looks pretty young. I'd say around 4-6 weeks.
Males can usually be neutered once the testicles drop, but are usually not done until about 4-5 months old. Females are usually done around 5-6 months.
It can be tricky to sex rabbits, especially if you don't know what to look for. Both have a bit that pops out, so you have to look carefully at that. Females look like a taco with a slit while males are round like a doughnut.
It doesn't look like a Jersey Wooly to me. They would have longer wool, even as babies. The colour does look like a blue though.