Do you go to junior high if your in January?

Answer 1

I assume the word "born" goes between "your" and "in january".

It doesn't matter what month you're born in. You go to whatever schools are provided in the area you live, or if you're properly enrolled at another location and someone (school or parents) pays the bus ride cost. A great many areas still don't have any such thing as junior high or "middle school" (6-8, 7-8, 7-9, usually), meaning most schools are K-8 and 9-12.

In Canada, you start school at Kindergarten in September if you will be 5 years old at the end of December, and at Grade 1 in September if you will be 6 years old at the end of December.