Kelley if you're going to keep domestic discus strains, which I would highly suggest over wilds for a discus beginner, I wouldn't worry about trying to acidify the water with peat. Monkeying with water chemistry is a slippery slope and generally leads to a lot more work and frustration than you need. I kept discus for decades in straight tapwater with no additives and they did beautifully.
Agree with Mark 100%.
Since you're just starting out with discus, keeping things as simple as possible is a prime first step to success. Pls. don't overcomplicate things for yourself, and in order to get off on the right footing, no matter what size of fish you begin with, I would suggest you re-consider your plan to go heavily planted. If you must have it planted, then think about limiting yourself to the minimums, i.e. very little substrate, just a few plants, and perhaps a piece of DW.
Do things slowly, a small step at a time, until you get some months of discus experience under your belt and feel comfortable venturing further afield. That's my best advice - along with ensuring you get the best quality, healthiest discus you can to start with - that can be 50% of the challenge beaten.