The most important tip is to find out from the shop what species orchid it is and look that up online BEFORE buying. Most orchids sold in ordinary flower shops are relatively easy ones to care for. Cymbidiums are common and beautiful. Here’s a site that list the more available ones, and here’s the whole shooting match.
But there are some species that are very sensitive to ambient conditions, and each has its onw requirements as to temperature, lighting, humidity and frequency of watering. Look up the target species and make sure it’s easy enough to handle in a living room. Some need highly controlled hothouses to do well.
What they need will vary greatly. The toughest ones to care for will require a room with controlled humidity, temperature that cycles from day to night, and exactly right amount and timing of light. I would definitely avoid the more finicky species for my first orchid. If the orchid bug really bites you, it’s a wonderful hobby growing them and you’ll end up with something resembling a hothouse, however makeshift it must be, attached to your house. You will also be treated to some of the most beautiful and fragrant plants imaginable.
I had to give mine up when I left California, but I had quite a menagerie growing out there.