I have two Ragdolls and they are absolutely gorgeous in every way. They were bought from a proper, ethical breeder after a huge amount of research though. They are the sweetest, gentlest cats and have never bitten or scratched me once even when I have to do things they don't like much such as clipping their claws.
They are like dogs and will follow you around all day just keeping you company. They run to the door when we come home and sleep on our bed. The female is so empathetic, she definitely knows if I am upset or ill and will stick to me like glue even more than usual, she is a real lap cat. The male (who is still quite young) is hilarious and cheeky and pretty bright for a cat - he can open doors, retrieve balls and soon works out anything he needs to work out. Both are really good cats and very loving.
As regards stimulation. They have a cat tree which they absolutely LOVE. They both sleep on it during the day and use it as a scratching post. The male is a climber and loves running up it and jumping down from it. They also have a tunnel and lots of other toys but they do get bored with toys so I rotate them - put some away for a while and bring them back out when they're bored with the ones they're playing with, that seems to work best. They don't need masses of stimulation though as they play with each other a lot. They do like playing with feather wands and with an LED pen in short bursts (LED pen is safer than a laser pen). They are very easy going.
I have a completely secure garden that they can go in and would NEVER let mine roam freely. Ragdolls are not supposed to do this, they are far too docile and will run up to dogs and people as they have no sense of danger or traffic sense. They are also very sought after and liable to be stolen. Mine show absolutely no interest in roaming and are not that bothered about going outside at all. I reckon if I stopped letting them out they really wouldn't care. They like to go and lie in the sun in the summer, particularly if I'm out there but that's it.
You don't need any fancy litter tray. We have a top entry one and use a corn based litter as that's what we find works best.
Different colour parents produce different patterned/coloured kittens. If you know what pattern/colour the parents are you can look up the possible types of colours/patterns the mix will produce.
The main thing is to get a Ragdoll from a reputable breeder. Ragdolls are generally a healthy breed but they do have two known genetic issues - a heart issue called HCM and a kidney condition called PKD. You need to make sure any kitten you buy has been screened for these. The breeder I used also made sure her kittens had echocardiagrams to check the condition of their hearts too.
Ragdolls do not like being left alone and really need other company. It's best to have another pet if you won't be with them for long periods of time. Even if you will, I think it's better for them to have company, mine really benefit from it. You don't have to have two Ragdolls, a non-pedigree kitten or a dog will do.