Can I compare this year's bookings with last year's so I can see if my business is actually growing?

Yes, as long as the system holds your bookings for both periods. Most reporting screens let you choose a date range, and the better ones let you place a second range beside it, so you can look at this September against last September, or this quarter against the same quarter a year ago, and see at a glance whether sales moved up or down.

It is worth comparing more than just your total sales. The same side by side view is usually available broken down by product type, by destination, by supplier, by branch and by the staff member who made the sale, which is where the useful detail sits. You will also want to be clear whether you are comparing by the date the booking was made or the date the customer travels, because in travel those two can tell very different stories about the same period.

The honest limit is that any comparison only reaches as far back as your data. If you started using the system part way through this year, there is nothing to compare against until you have a full year behind you, unless your older records can be brought in first, and whether that is practical depends on what shape they are in and whether your previous system or spreadsheets can export them cleanly. You also need to compare like with like, so decide whether you are looking at gross sales or at what you actually earn, and whether cancelled bookings are counted or stripped out, because mixing those makes a growing year look flat and a flat year look like growth.

Before you rely on it, check whether the reports you plan to use offer a comparison date range at all, settle on the one figure you will treat as your headline number, and raise importing your historical bookings early rather than after you have gone live.