Roughly..... sign contract with HR and get sent to medical for Igama medical etc, your Igama will be ready in a few days, then you can apply for family visa, make sure that you ADD all family members during HR paperwork.
Visas are done in a few days and will be available in whatever embassy you stipulated, so theoretically family can join you within the first month. BUT do you want them to do that??? The answer is NO. Finish your training first then bring them, school year starts Sep so no need to bring them until then, not to mention that you may be bonded so school fees will be a nightmare.
There are some days off during ground school, you might be able to get home, but because your predecessors took advantage of this, many training managers are loath to allow people leave.
Enjoy