My two cents: If that was your first 5k, your feet probably don't have a lot of miles on them yet, so you are likely to hurt some, even if your biomechanics are perfect. Speaking of, there must be some reason why the heel pain is only on the right. If you are like most people, including me, your right and left legs/feet are not exactly the same. One arch may be lower than the other, or there can be a slight difference in leg length, which is very common.
I'm going to guess that they sold you motion control shoes that had such stiff arch support, you were running on your arches in that race. The simpler shoes you had before did not produce that problem, but low arches have a tendency to roll inward (pronate) more than a medium arch would, and that rolling can cause the heel pain if it's on the inside of the heel.
If you stick with the new shoes, your arches may eventually toughen to the point you don't notice it any more, but your arches weren't really meant to bear that much impact when running. There are ways to modify shoes so the foot won't roll, even if the arch is not built up to prevent excess motion. One way is with a small amount of padding under the main ball of the foot, which allows the ball to plant sooner to support the weight, making the roll unnecessary. Some orthotics have been made for this purpose. You can also have a sports doc or podiatrist order a custom set to place in your shoes.
The way you move your legs and feet when you run (biomechanics) is a complicated subject that you can spend a lot of time and money dealing with. There are ways to train biomechanics through targeted exercise, but much of it is based on the way your body is put together. Sometimes, you just run with what you've got until you get used to it. Most runners have several sets of shoes, and find that they get different results even with the same model from year to year. You might find something between these last two pair that you can run comfortably with. Best of luck in your training!
