There is more to Peach then just "Using turnip a lot," and "Use down smash and neutral air a lot." I am not the best Peach player, but at least I have some familiarity with her.
So just like any other character, before you even learn how play her in Neutral, I recommend learning your characters tech's first. In Peaches case, a crucial one is quick float cancel Aerial (Ask me if you don't understand any tech I mention), using different float heights for certain situations (that is something you have to look up), and chain grabbing Fox/Falco. Those are basically all the tech you need for her as a beginner for Peach, but I wouldn't stop at that. A very under used tech that Peach has is Jump Cancel (Which is basically jumping on the ground, and very quickly jumping again between the first 2 frames in the air), what this does is makes Peach go into a squat position and let's her act out of it as if she had 0 frames of landing lag. So what does that mean, and how can it be used? Well instead of Shield grabbing (which takes 7 frames, and is unsafe), you can instead Jump Cancel out of shield (Since Peaches Jump Squat is 4 frames, you have to take that into account, but that still leaves you with 3 extra frames to act out of compared to Shield grabbing) and then you can literally do ANYTHING. I mean anything, you can Down smash, jab, Up Smash, Tilt, anything you want really. Frame wise it's "best" to do a jab out of Shield, but realistically it's WAYYYY better to Down Smash out of Shield, which in total is 9 frames (4 frames from Jump Squat, and 5 from Down Smashing), so it's only 2 frames slower then a Shield grab, but is so much better and covers more ground. No more do you need to be scared of Shielding, now your opponents will be scared to approach your shield, and it will force them to respect more of your space, since Down Smash out of shield is soooo fast. Oh yes, the way I do this tech is pressing Y and then quickly shift my finger to X, but it's up to you.
As for Peach in Neutral...... I am not so familiar with that, but what I do know is that there is a lot of punishing unsafe Aerials with crouch cancel into Down Smash. But there is of course much more to her then that, what I would recommend is watching top player Peaches play while studying them, and looking at Threads about how to play Peach in Neutral.
