I often see brown spots on the leaves of this plant. What do you think is the best way to prevent it? Do I have to have special fertilizer?
Most often, these brown spots are caused by water or pests. So if the problem is water, try not to overwater, but if it is pests, make sure the humidity and temperature are proper.
Don't worry, it's probably just because it was in too much sun. If that's the case, I think you should try to find a spot where it can get some bright, indirect light.
It looks like your plant is getting too much sunlight. I'd suggest moving it to a slightly shady spot where it can still get some sunlight.