When could you start working? Do you have a family that needs to be transported?

This question relates to the candidate's personal circumstances and is not connected to technical skills or knowledge of Golang. It is better to answer honestly and briefly in an interview, for example:

"I can start working from [specify date or period]. I have no family circumstances requiring relocation, or if there are, briefly describe the situation and readiness to relocate."

It is important to show readiness and transparency regarding organizational matters.