From the rest of Canada, or from the US Mainland, you get to Nova Scotia on the /Transportation-Canada Highway. Nova Scotia's # 104 starts at Amherst on the New Brunswick border, and continues to North Sydney on Cape Breton, where you can catch the ferries to Newfoundland. But, if you want to get to Halifax, you connect to highway #102 south at Truro.
From the rest of Canada, or from the US Mainland (via Amtrak), you can catch VIA Rail into Nova Scotia with stops at Amherst, Truro and Halifax. The CN Rail station is right downtown at Barrington and Cornwallis.
If you arrived by ferry from either Bar Harbour, Maine or Saint John, New Brunswick, you'll drive into town from Yarmouth or Digby via the #101 along the Fundy shore, or possibly viea #103 along the Southern Shore.
Halifax is alos one of the world's largest container shipping ports, and regularly receives ships from aroudn the world. YOu can see the shipping schedules at the Port of Halifax web site, which may present some opportunities for passage to other parts of the planet. Please note that if you are planning to ARRIVE from abroad, you will need to have the proper visas in order before departure, captains are liable for a hefty fine (roughly $50,000) for "stowaways".
Ahlifax's international Airport, 40 minutes north of town at Elmdale, serves a number of airlines serving regional, Canadian, American and International destinations