For the most part, there is pretty clear definition as for what action is legally considered a right and what action is considered a privilege. (E.g. you have a right to walk on your own property, but not someone else's unless they give you permission to do so, in which case that permission would be a privilege.)
But let's keep legal definitions aside for a moment. Let's also keep actions aside for a moment, and instead talk about things, especially things like access to healthcare, access to education, being loved, to name a few. Some of these things are pretty important for a good quality life yet they are considered to be privileges. If you think these are something that everyone ought to have, then by definition, you're thinking that these should not be a privilege but a right.
Everyone agrees that no one should go through an abusive childhood, i.e. having non-abusive parents is a right. But where do you draw the line about what is abuse? If parents don't take care of their child's mental health, is that abuse/neglect? What about parents who spank their child? This is where things get hazy, because morality and personal experiences and subjectiveness come in. If you feel that something ought to be a right but others don't, then don't think you're wrong just because you're in the minority. In some ways, that thought itself is a privilege.