I filled my tub up with water and lysol to clean. I end up forgetting about the water in the tub. When I remembered the water and lysol was in the tub I found the water was gone. A few hours later I went to the garage and smell lysol then realized that the ceiling in the garage was wet. The shower and the tub is separate and I've used this tub approximately two times. Please provide some suggestions of what could be the problem.

Sounds like the seal between the drain and the tub is gone. It usually is done with plumbers putty and can dry out over time. Is this tub and drain old? It also could be one of the joints in the drain which could only be found by opening the access panel and inspecting it. Once things have dried out it will be easier to find than when everything is soaked. Get it done though, leaks like this will cause major destruction over time.

This home is only a couple years old and I'm the first occupant. I called out a plumber who indicated that something needed to be tightened through the drain and did so with some sort of tool. I afraid to use the tub because I don't know if the problem is fixed, but guess that would be the only way to see! Do you know what the tool and the problem he is describing?

Use the tub. The drain seal may have been too loose and the plumbers thinking is he has it fixed. Using the tub will prove or disprove him right, go ahead. Plumbers have all sorts of wrenches a home owner will never need, some are made or adapted by the plumber. Take it for a ride.