There is suffering. or Life is suffering.

All existence is suffering.

It's usually translated as "Life is suffering", but the actually word in Sanskrit is "Dukkha", which means something like "a wheel out of kilter". Typical explanations talk about how riding in a wagon with an off-kilter wheel is uncomfortable, what with all the bouncing around. A more modern and thorough translation would be "unsatisfactoriness permeates life": not getting what we want makes us dissatisfied, or having what we want but being anxious about losing it. Then there's old age, sickness, death, etc. Basically, there's all sorts of unpleasant and unwanted experiences that come with being alive. That's what it's talking about. Buddhism is focused on this problem of "dukkha" or our chronic dissatisfaction. It takes a radical solution relative to other religions: instead of promising that this suffering can be eliminated or that you'll get to heaven someday, it says that there are specific causes of the suffering, some of them you have power over and some you do not. The former are addressed by removing the causes of the suffering, the latter are addressed by learning to bear the problems in a way that transforms the quality of suffering. It doesn't mean there's no more pain, but the anxious resistance can end, and that alters what it means to suffer.