sweet deal you got the sump in.
Yes many people are supprised to see the construction of these stands. But the stand is much stronger than they appear because the wood is vertical and all the weight is inline so it goes stright down the vertical parts of the stand and then is transfered to the floor.
Dont panic about the plumbing. Lay all the parts out and then just invision what you would need to connect to what inorder to get the hose from point a to point b.
Your pump is an external pump so one thing you want to do is put some vibration damping materal under where the pump would sit. Then you wnt to position the pump in respect to the sump.
Your sump should have a bulkhead hole in the side for the plumbing to connect it and the pump together. The bulkhead may or may not be installed. If all you have is a large hole then you should have bulkhead parts that you can put into that hole to not only seal the hold put provide a point to attach the plumbing to go to the pump.
To ease the setup start at one end of the system and plumb back. For example start with yoru return lines and plumb them back to the pump and then the sump. Then work on your supply lines.
Dont be afraid to post a trillion pics of the setup if you get lost or confused. Also, maybe you could entise Casie to come over for a few cold adult beverages
in exchange for getting help on your plumbing.