Chinchillas are not known for staying still, nor are they considered especially sturdy as pets. They are not good pets for a young child, due to their light bones and easily-stressed nature.
Chinchillas do not like being grabbed and are afraid of quick motions. They will happily take food from hands and some may be content to stay close to you for a short time before they bounce away. On their own terms, a curious chinchilla will be happy to approach you and may even enjoy a scratch to the cheek, ears, chest or behind the front paws. A happy Chinchilla may turn their head and close their eyes whilst before stroked, a Chinchilla that doesn't want to be touched may chitter or scold you.
Scooping up your Chinchilla and holding them against your body can protect from long falls. Hold them firmly, without squeezing, and let them perch on your arms.
Chinchillas can free-roam, but this absolutely must be in a safe space and for limited amounts of time. They are very prone to stress and can have fits if they become overwhelmed in an empty space. Short but regular sessions are best to avoid stress and the risk of over heating. Never put a Chinchilla in an exercise ball.
Remember your Chinchilla is very good at jumping and can easily find a fallen cushion to jump to the sofa. May sure there are no long gaps and that any dangerous items are tucked away. If there is a lead or skirting board that can be chewed, or some food they shouldn't eat under a space you didn't think they could fit in, they will find it!