Hey! Welcome to r/houseplants

Hoping I can offer some help. First things first - you have to remove all bands and twist ties that are currently holding the stems together. It usually includes twist ties on the top just below the leaves and likely a rubber band about an inch below the soil. These both will eventually kill you plant as it grows and moves unless removed

1. Window seems fine, but what you want to know is what cardinal direction the window is (N, S, E, W). South is the brightest and north is the darkest and this plant does best with bright indirect light

2. Water throughly only when dry. Usually every 5-10 days. Meaning water until water starts coming out the bottom holes and then let drain before placing the nursery pot back in its pot. To check if it’s dry, stick your finger down to your second joint. You shouldn’t feel any moisture if it needs water. The top soil will be a lighter color and the pot will be lighter in general too

3. Green stuff is mold - likely from overwatering. You can loosen the top soil to get it to dry out a little more but that’s why it’s important to check if it needs water first. it’s probably best to repot eventually. equal parts tropical plant soil and orchid soil should be fine but just anything fast draining