Welcome to Piloteers!
If you were competent enough to change the Pontiac timing chain, you have the skills to at least pull the front cam gear cover and take a look at the belt. Unless the service was done at a dealer, the first clue that it's been replaced will be not-Honda branding on the back of the belt, and from the wear on it you might get a hint of the miles on it. There will be other clues, like wrench/tool marks on things you can see like the motor mount bolts at the belt end of the engine, plus the bolts that hold the PCM bracket, the ground wire screws around the motor mount, stuff like that. If they've never been disturbed and/or there's no other evidence that it's been done before, you should be budgeting for the belt replacement sooner rather than later.
Whether you can do it yourself is a judgement call you get to make. My own wrenching skills were growing during the same time window yours were, albeit on non-American cars for the most part. I had to get some guidance on American V8 timing chains; I was used to long chains connecting overhead cams on Italian and British engines. The WSM for our Pilots is available in from a forum post here in the last few years, and You Tube seems to be a good place to get visual instruction on the task. In the last few days a member shared that he put in 11 hours in one day and finished the job part way into the next day. I suspect that I could pump out the work in a fraction of that amount of time after a few practice sessions. The first "learning" episode would get that extra time budgeted, even though all the parts and tools would be lined up well in advance. For me at this point, it's therapy anyway.
