Buying your first houseplant: a guide that starts with your windows
Nearly every failed first houseplant failed for the same reason: it was chosen because it looked nice, in a spot that could never support it. Start with the room instead.
Work out what light you actually have
Face the window and note the direction. South-facing windows give the most light through the day; east gives gentle direct morning sun; west gives harsh afternoon sun; north gives steady, weak light and no direct sun.
Then measure distance, because it matters more than people expect. Light falls away sharply as you move into a room — a plant three feet back from a bright window is in dramatically less light than one on the sill.
The practical test: at the spot you have in mind, on a clear day with the lights off, can you comfortably read a paperback? If not, that is a low-light spot, and you should choose accordingly rather than hope.
Then be honest about water
Are you the sort of person who will check a plant twice a week, or the sort who will remember it monthly? Neither is wrong, but they lead to different plants. Most beginner failure is over-watering, not under-watering, because watering feels like caring.
Good first plants, by situation
Bright indirect light, average attention: pothos, heartleaf philodendron, spider plant. All three are forgiving, grow fast enough to be satisfying, and visibly tell you when they are thirsty.
Low light, low attention: snake plant (sansevieria) or ZZ plant. Both tolerate genuine neglect and dim corners, and both die quickly if kept wet.
Bright direct sun on a sill: most succulents, jade, aloe. Note that these want real direct sun, not merely a bright room, and that a windowless bathroom is not a succulent home.
Some humidity and a bit of attention: peace lily, which dramatically wilts when thirsty and recovers within hours, making it an unusually good teacher.
What to avoid at first
Fiddle-leaf figs are sold to beginners constantly and are a poor choice — they want a lot of light, hate being moved, and drop leaves at any change. Calatheas and marantas are beautiful and want humidity and clean water most homes do not provide. Ferns dry out faster than a beginner's watering rhythm. None of these are impossible; they are simply a bad first experience.
In the shop
Tell them the direction your window faces, the distance from it, and how often you realistically water. Any decent shop will take it from there — and if the plant they suggest is not the one you walked in wanting, that is usually a sign you are in a good shop.
Check the pot has a drainage hole. A decorative pot without one is the single most common way a healthy plant is killed in its first month.