The easiest way to get started is to find the TripAdvisor listing for a place you want to save to your trip. Click on the "Save" link (which appears as a bookmark icon on mobile devices) near the top of the page. You'll be asked if you want to create a new Trip, or add to an existing one. When creating a new Trip, you'll be prompted to give it a title (don't worry, you can change it later if you like). At that point, you can either view your new Trip or keep browsing TripAdvisor for other places to add.