It could be condensation dripping down. One of the biggest reasons for that is a leaky flapper valve which causes the toilet to run to refill the tank periodically, adding cold water which can cause things to sweat. Simple fix, replace the flapper valve, a 1-minute task.
Does the toilet rock at all? It MUST be sitting firmly on the floor. If it rocks, it needs to be reset with a new wax ring and shims. The wax is not resilient...once it gets squeezed out, it won't flow back, so the seal could be broken.
If the toilet is a two piece, and the tank can rock on the bowl, the gaskets might be unable to maintain the seal...it might just need to be tightened up a little.
Those are the to most common things, and well within the maintenance level of a semi-handy person.