I was in your shoes a couple of years ago, however my situation was for a road trip across the USA, not Thailand, but the same principle applies and here is what I think you should do:
100% buy the DLSR. You will be happy that you did.
Although you may not be able to afford extra lenses yet, DLSR's offer a wider range of possibilities with interchangeable lenses and better control over your camera to really accomplish exactly what you are looking to achieve from each shot, especially with the control of depth of field, considered one of the most instantly "stand out" features that make certain pictures look professional and give them great character, giving most of the focus to the subject (although DOF is rarely used in landscape photography which you will probably be doing a lot of in Thailand). The A2400 does not offer as much control over the camera and your photos simply won't be of as good quality as the would with a DSLR.
"But wait a minute, you can't say that, the A2400 photos may be of better quality because keeping the A2400 means that they can take the course and therefore learn about composition and other concepts that they wouldn't if they bought the DSLR.."
I know there will be a lot of people that say "education is more important" and that "a bad workman blames his tools" and so on.
I totally agree that education is important.
So - WHY pay to go on a course with your compact? Well to learn I guess? Right? That is what we want, someone teaching us, someone walking us through the steps, diagrams and graphs, examples and tips.
This information is invaluable. If only there was some way of getting this information for free right? Good quality information with diagrams, tips, guides, walkthroughs, comparisons all the learning that you could possibly want, in a visual format all in one place, available anywhere at any time that could be watched over and over in case we miss anything - for free.
Hmm, if only..
YouTube - Use YouTube to learn. Youtube is the largest content sharing website in the world and offers an amazing selection of top quality videos about photography. Half the world (not actually) is using YouTube to learn new skills all the time, I just recently learnt how to develop colour film at my house on YouTube. There are so many channels on YouTube dedicated to teaching photography.
Think about it this way. If you do take the course, you will turn up with your A2400 and a lot of the stuff they will go through will likely be to do with controlling your camera on manual: aperture, shutter speed and ISO, which you will not be able to do with your camera anyway.
You are much better off buying the DSLR and learning to use it. Self-teach, go out and take some shots and, with the help of YouTube, you will improve.
That's what I, and I'm sure many others did, and what I suggest you do.