Keep it simple--Use good water (no chlorine or chloramines) and stick to the recipe whether you do extract, minimash, or AG.
For a year or two my biggest challenge while brewing was that I didn't stick to the recipe.
I'd get "inspired" to try and get fancy with whatever's laying around the kitchen (spices, adjuncts, etc.)
Not all of the beers turned out that great, or, said another way, would have been much better if I'd just stuck to the recipe.
I also took awhile to get the water chemistry issue--it's a big deal.
Definitely spend a few bucks on using better water if your local water profile is awful.
Many brewers just use distilled or RO water and build up the water profile to get what the style calls for.