Is playing D&D 5e with two people feasible, particularly with the Starter Set adventure?

My girlfriend and I want to get into roleplaying games, we’ve both been interested in trying out Dungeons and Dragons. She has never played a pen and paper RPG before, I’ve played the Swedish Drakar och Demoner (DoD) once in school. We don’t have a group yet, so we thought we’d start out with just the two of us.

We’ve bought the D&D Fifth Edition Starter Set, but I’m not sure how well the game will work with one of us as the DM and the other as a player (I will probably be the DM for our first campaign). Is this feasible? Will the example campaign in the box work well enough for us to get started? How can we get started playing one-on-one 5e effectively?