I had passed my driving test,--(get)my licence in few days.此

and I would get 过去将来时.因为前面的had passed 是过去完成时,强调在一个过去的动作之前完成,所以决定了后面也要用过去时.
in few days 意思是几天之后.要用将来时.
综上,应该要用过去将来时.