Inverness Airport is the closest, but since you need to hire a car anyway it's better to use Glasgow Airport. Glasgow Airport has a better choice of flights and fares. Turn west onto M8 and cross the Erskine Bridge to join A82 northwards past Loch Lomond; maybe 2 hr 30 min to drive. Oban Airport has flights to the Hebrides (effectively a flying school bus) but no connection to the mainland air network.
Trains from Glasgow Queen Street take four hours via Dumbarton, Helensburgh, Arrochar & Tarbet (for Loch Lomond), Crianlarich (where a portion divides for Oban) and Spean Bridge. There are five daytime trains M-Sa and two on Sunday. They continue west on the scenic West Highland Line to Glenfinnan, Arisaig and Mallaig, for ferries to Skye.
Stations, car parks and charge points around Fort William.
Car parks in and around Fort William. Check the tariff board on arrival.
Public charge points in and around Fort William.