It's nice that you already have the equipment. That's a major leg up.
My pond has an aerated bottom drain and water is drawn from there and from the skimmer. Those 2 pipes are joined right before they get to the pump. Then the water can go either through a series of UV lights, or those can be bypassed. Then it goes to a large pressure filter and back out to the top of a waterfall where it runs back into the pond. We haven't used the UV lights for a few years now, so the water goes right from the pump to the filter.
The skimmer is directly across the pond from the waterfall. There is also a float switch in the skimmer that will cut the pump off if the water level happens to fall to a certain level. That should keep the pond from getting pumped dry if there is some diversion of water somewhere.
The filtration system is in our garage and there is limited space there. So it's pretty well packed in. This is how it looks:
View attachment 137816
Pipe from the bottom drain is on the right in the picture. Pipe from the skimmer in is the middle, and the pipe next to the filter is the return to the pond.
Hope that is of some help. My nudge would be that I wouldn't have a pond without a bottom drain, but that's my preference. It certainly is not everyone's and we are all entitled to our own ways of doing things. As long as it works for you, it's all good.
This is also my first and only pond, so I've not done it any other way. I'm very pleased with the results, as are most people here with the choices they have made.