Bought A Used Tank & Sump, No Clue How To Set Up

HI I bought a used tank a few days ago and it came with a sump and some pipes and I don't know where anything goes. This is my first saltwater aquarium and any help would be much appreciated. Thanks

 

Two more photos in case it helps at all

 

Is the main tank drilled (holes in glass walls so water can drain out) ? Or is it a DIY overflow? (A tube of some sort going over tank wall so water can drain?) .First you need to figure out what you actually have. I recommend a Herbie or beananimal setup (see links below).

These are good articles to help you:

Common Aquarium Overflows - Durso, Herbie and Bean Setups | gmacreef

Herbie Overflow Plumbing Guide for Quiet Reef Aquariums - gmacreef

 

The only holes in the tank are the two under the tank in the left corner in the photo

 

Looks like you have a corner overflow with all the pipes and plumbing you need.
Get Teflon tape and wrap every connecting part.

The link here is a PDF to a reef ready tank by Marineland, which should be about the same installation process.