Are you looking purely for a 2 player game? Patchwork is a good one (and the theme is quite quirky).
Carcassonne isn’t that complicated (at least the basic game isn’t - if you add in some of the expansions that are available it gets much more complex), and works well enough with 2, though it’s really best with 3 or 4 people. It’s often seen as a ‘gateway’ game, i.e. a gentle introduction to the modern style of board games. Ticket To Ride is another good game in this sort of category (and has a travel theme).