I know light roasts tend to have these flavors more. How can I brew to maximize these flavors? I use an Aeropress, but any answers are useful.
Lighter roasts are going to have more of these flavors but it obviously depends on the bean as well. If all you are going to change is the method of brewing the coffee, I would recommend making sure you don't use too hot of a water temperature and trying to use a pour over. I find pour over allows for more delicate flavors you are describing, rather than something like aeropress which can approach more espresso type coffee.
I know this is not a standard method of brewing, but cold-press coffee tends to have lighter, fruitier notes. And by fruity, I truly mean fruity. Like nothing you've tasted before.
No heat is added, so you will absolutely reap the benefits of fruity, light notes, while reducing acidity. The process is heavily explained all over the web, so do a quick search for the proper method. It's very easy, but requires about 12-24 hours to brew. In exchange, you will have a concentrate that can last for a few weeks before it becomes oxidized.
Since you are already using an AeroPress, I would look for ways to get the flavor you want with the tools you already have. First, make sure your water isn't too hot. I've seen recommendations for as low as 185F which is far below boiling. You would need a thermometer to accurately gauge the temperature, but at the very least make sure the water is well off the boil before you add it. Second, don't leave the water on the grounds for too long. The longer the water is brewing, the more bitter notes will be extracted. Finally, a bit coarser grind might also help. The usual recommendation is for something slightly finer than what you would use for drip brew. You might try something slightly more coarse and see how that goes.
If none of that works, of course you could always switch methods. Good luck.
Lighter roasts keep more of their single origins nuances, but it's the variety, origin, and wash process that determines what the flavors are. The brewing process is about extraction. The balance of sweet/bitter/tannin/acid/flavors can be affected by your brew process. I find that acids and fruit go hand in hand, and so the perception of the fruit flavors can be enhanced by acids. Doing a cold brew I find is amazing for dark roasts, because it subdues the acids, and the dark chocolate/woody flavors don't work as well with a lot of acids in my opinion. I believe an espresso brings out maximum acidity/brightness for any given coffee, and you get a lot of citrus notes, but that might be too bright to taste the sweet flavors you're looking for. That means you want something in the middle just erring on the side of bright.
I would recommend this: find a Panama (or other central/south American origin) dry-processed (aka "natural") and brew it with gentle pressure for sweetness.
Dry-processed/Natural coffees are dried out with fruit flesh on before its removal, which allows the sweetness and flavor of cascara fruit seep into the beans. Washed/Wet-processed coffees have their fruit flesh removed immediately, so they tend to have a cleaner coffee flavor.
Try espresso. The short extraction time accentuates brighter, more acidic tones, and might bring out fruitiness, with less of the bitterness that comes with longer extraction times. The fact that it is brewed quickly and in an enclosed chamber might concentrate more of the aromatics. I'd also suggest a manual italian lever press. They work wonders for light roast.