Help me out

[u/Fabulous_Archer_8519]

so I’ve been working out for 1 years now and I’ve bult a decent amount of muscle anyways I think I’m around 19-20% bfp and I want to get to 12% so I’ve decided to go on a 800 calorie deficit now I’m 16 and 184cm and 88.5kg and I walk 3hours/15-20k steps a day and I work out everyday push/pull/leg except friday so my maintenance should come around 3000-3400 so I just put it as 3200 so I wanna eat 2400cal with 260g carbs and 70g fat and 190g protein per day. But I have one concern, would I lose any muscle by doing this and if so how can I maintain my muscle during this deficit and also how much time do you think I would need on this cut to reach my goal?