inabw Bristol GS will divide subjects into modules and you take one module at the time. The first module in Bristol consists of the following subjects:
022 – Instrumentation
061 – General Navigation
050 – Meteorology
040 – Human Performance and Limitations
It sounds like you have bought a course from a third party provider (school), so it's best to ask them what way they expect you to complete things.
I did the course directly with Bristol and the way I did it was I was focusing on the 4 subjects at hand and doing bits and pieces from them as I go, pretty much following ATPDigital pattern