A kitten seems the obvious choice: small, cute, and it will grow up "to fit you". In reality a cat's character is largely set by genes and the first weeks of life, and raising one to order works less well than people hope. An adult cat is not a compromise but a separate option with its own advantages.
A kitten
Pros. You get to watch it grow. It is easier to introduce to a dog or children — kittens adapt faster. From day one you can get it used to the carrier, nail trimming and having its ears checked.
Cons. The first six months are energy without brakes: curtains, cables, attacks on feet under the duvet at three in the morning. The character is unknown: a quiet kitten can grow into an independent cat that does not like being handled. It takes time — a young kitten should not be left alone for long. Vaccinations, neutering and the first vet visits are all still ahead.
An adult cat
Pros. You can already see the character: affectionate or aloof, chatty or quiet, whether it gets on with other animals. It is usually litter-trained and uses a scratching post. It is calmer, which suits people who work long hours. In shelters and foster care adult cats wait longer for a home than kittens do, and their chances are lower.
Cons. It may bring habits you will need to reshape. It often hides for the first days: settling in takes from a few days to a couple of weeks. If the cat is over eight to ten years old, ask about its health in advance and be ready for vet visits.
Who each one suits
A kitten — if you spend a lot of time at home, are ready for some damage and want to go through it all from the very start. Two are better than one: together they play with each other rather than with your hands.
An adult cat — if you work in an office, if there are small children at home who need a calm animal, or if you want to know in advance who you are bringing home.
Older people are usually better suited to a calm adult cat: a kitten under your feet is a real risk of falling.
What to ask the previous owners or volunteers
The cat's age and where it comes from. Whether it is neutered and which vaccinations it has had. How it feels about being handled, about other animals and children. Which litter tray and litter it uses and what it eats — it is best not to change anything in the first weeks.
Either way
For the first days, one quiet room with a litter tray, water, food and a hiding place. Let the cat come out to meet you on its own terms. In the first week, see a vet even if there are certificates. And create a profile in Mr. Petman: the vaccination schedule and reminders are worked out from the cat's age automatically.