You can drive but you cross Canada. The Al-Can Highway is the road you'd drive.

Alaska is not connected to the US. It's only land border is Canada.

But it's not surrounded by water, so it's not like an Island.

You can also drive onto an Alaska Ferry in Seattle, WA that would take you to Alaska.

There are cities in Alaska that do not connect anywhere by road. The Mountains are too severe and no roads have been built to.. Juneau the Capital is one such city. You can get there by Boat (including Ferry, so you can take your car) or by plane.