of course haha. ive mained peach for awhile now, and while i dont have quite the level of technical precision that those guys have, i do know a lot about the character, so im glad to help out any one with a question. but yeah that stuff just takes a lot of practice, and when executed, you have little margin for error, or else you will end up in an unfavorable position, meaning you have to execute quickly and precisely. if you are just getting used to the character, i recommend going into training mode and just WDing around to get used it (peaches WD is unfortunately the most timing strict of all the WDs, if you hit L/R to early or late you will just end up doing an obnoxious, quick float that is years slower. you have to get it just right). also, in the same manor, just jump up, float, and practicing FCing your fairs. when you get the muscle memory, it will be to the point where you have much more control over the execution, and will be able to do it quicker, more spontaneously, and with less initial start required from you thinking about doing it to actually doing it. just having a lot of comfortable control over peach (and really any character that you plan to main) is the overall key to getting better with them, as you can probably guess haha.
in regards to FCing, i would also practice being able to run > immediate float > FC nair. this maneuver is a really good substitute for dash attack when the opponent likes to shield a lot, as you can follow up with a guarenteed jab smash or sometimes grab. more generally, floating directly OOS is very useful for those who like to space attacks.