DD was about a year old. She wasn't good at it for a while, but I let her use it.
DS uses one but not well lol. He puts the food on the spoon/fork with his hand then puts the spoon/fork in his mouth
He just started really getting the hang around 20 months but we started letting him try around 18 months.
My nephew was around 18-20 months when he fully used a spoon with no issues(issues being flinging food & grabbing the food off of the spoon to eat it)
Elliot is 16 months and pretty good at it...spoons are messy though
My 15 month old has been using forks and spoons for a while now with pretty good accuracy! My older son started much later, so I would think there is a huge range of when they start :)
My son was around 4 months old, but he's always been VERY independent and had an obsession with doing things that his uncles could do. He's just over 2 now, but I remember him crying and crying at the dinner table when he was 4 months old and wouldn't stop until I put him on the table by the pan of spaghettii sauce and he reached over, grabbed the serving spoon and sucked it clean and dipped it again (first food and he gave it to himself). He's been feeding himself ever since. It's just gotten less and less messy.
Point being, it really depends on the child but they can start pretty early. If they don't though, its nothing to be worried about. They all develop at their own speed.