It depends on what breed of hamster you are getting because all are very different.
I only have experience with Russian Dwarf hamsters so I can help out with that aspect by giving you pros and cons on having them and some facts after.
Pros
• Once a bond is formed with a Russian Dwarf hamster they're very loyal and will trust their owners 100%
• They're more active than Syrian hamsters, so although nocturnal they may get up during the day and run around
• Russian Dwarf hamsters are very entertaining to watch as they love running around
• They're cheaper than Syrian Hamsters due to their small size which mean you don't have to buy the huge expensive toys or huge cages (they do need to be big enough for the hamster though)
• As long as you clean the cage at least 3 times a week they won't smell
Cons
• If you forget about your hamster it will most likely become very violent and angry at you
• Pet stores recommend you get them in pairs however do not. Russian Dwarf hamsters are independent and live better on their own if you are to put them in a cage with another Russian Dwarf they will fight which can lead to them killing each other.
• They're easily scared by things such as loud noises, strong smells and sudden movements (a way to check if they're scared or stressed is by their ears if their ears are flat on their heads you should leave them alone and keep them in a quiet room so they can calm down)
• Like all people Russian Dwarf hamsters have their own personalities so there is a chance that the hamster you get can be violent. This is why I don't recommend going to pet stores to get them although pet stores say they look after them, they do not. I've witnessed it first hand. They handle the hamsters very violently which then leads to the hamsters becoming violent out of fear of what has happened to them.
• Yes, They're a handful (at first). At first having a hamster it almost seems like a chore so you need to make a schedule, this is what I found best, if you keep to that schedule after a while caring for you hamster will become an everyday thing.
Facts about Russian Dwarfs
• Russian Dwarfs are very good at hiding pain so if you see something on your hamster which looks out of the ordinary it's best to take it to the vet.
• (this applies to female hamsters which in my opinion are better to have then males)
Female hamsters do PMS and also have periods, they just don't pass blood. It only lasts a day though, however during that day you may notice that either your hamster has not come out of where it is sleeping or it is not in a good mood. When that occurs it is best to just leave it alone maybe put in some snacks (I like to give my hamsters cheese when I notice they're feeling grumpy, make sure the cheese isn't too salty and it's only a small slice)
•Russian Dwarf hamsters are prone to diabetes so although some sweet things you can give them do not give them a lot, this is the same with diarrhoea
•Russian Dwarf hamster can eat human food just in small quantities.
Foods you should not feed your hamster
Almonds
Celery
Chocolate
Garlic
Kidney beans
Lettuce
Onion
Peanuts (however you can give them one a week as a treat make sure it's unsalted though)
Potato (sweet potato is okay)
Spicy or seasoned products
Sugary products
Tomato leaves (extremely toxic to hamster)
Unwashed fruit or veg
Chicory
Cauliflower
Broccoli
Pear
Peach
Banana
Citrus fruit
Foods you can give as treats (only give them in small little cubes and not very often)
Apple
Carrot
Cucumber
Hard boiled egg
Meal worms
Kiwi
Brown bread
Uncooked pasta
Crackers
Cheese
I hope this was helpful :)