Welcome!
ah gate way dru... um, I mean Koi.
1. If you can find a complete system, that's great. If you can't get a whole package and you've got some patience and willingness to stay on top of the FS board on here, you can probably piece together most of a system in a couple of months.
2. Titus mentioned it, but buy the best equipment you can possibly afford, specifically the best skimmer and best lights you can afford. $150 bucks might look like a steal compared to a better, $300 unit, but 99 times out of 100, you'll end up replacing the bargain piece of equipment in 6 months because of poor performance. It effectively turns your $300 purchase in to a $450 purchase.
3. Make friends with at least a couple of forums. They're an invaluable repository of experiential knowledge, but always keep in mind that as good as they are, you can't always trust the quality of the information. The number of "old wives tales" that get repeated as fact on the internet may actually dwarf the good information, so you have to develop a way to critically sort through what you're reading while making decisions about products, methods, and inhabitants. It gets easier with time.
4. There are 90 ways to skin every cat, but there are some things about reefing that you can't avoid. You need an intentional system to deal with nutrients (phosphate, nitrate). There's literally dozens of methods and accompanying products that range in terms of maintenance, cost, and simplicity. They all have their proponents, drawbacks, success stories, and horror stories. They also all have their groupies and haters. Research a few of them in depth and pick a system that makes sense to you, works with the kind of tank you want to keep, Then, understand how and why it works, and set up your tank around that. Not tackling nutrient export with the same care and intentionality as how you choose your lights and plumbing will cause you no end of headaches.
5. And lastly, know that 'reef safe' is a relative term
