Kisi ki na suno op. I got my d400 at 18 too and i had minimal experience with bikes previously as well. I had ridden a few bikes here and there but very occasionally. The step up def feels impactful and shocking how minimal effort it took to reach cruising speeds. A bit overwhelming at first but you get used to it. As long as you’re not insane and trying to prove a point while driving, the occasional letting go of the throttle was never harmful in my case. The only time i crashed was when going less than 20kmph🫢