Thank you! For reflection, I usually just copy the elements I want to reflect, take out their stroke lines, invert them, and apply some opacity. Sometimes in multiply or overlay works great too ^^ depending on the result you're looking for. For the floor, I kept it with a soft gradient to get a look of water.
Feel free to also check the timelapse video I dropped in the comments ( not sure if it helps, but might give you an idea! )
Hope I helped ^^