If the source is not a connection from above then your disposal needs to be replaced. Try cupping your hands around the very top under the sink while running water. The ring that seals the gasket turns clockwise to tighten. The only other repairable leak would be where the piping comes out the side. There can also be a smaller dishwasher drain hose above that.
Not every garbage disposal was created equal, and it can be difficult to discern which one is right for your home. After all, a quick internet search will show you that there are hundreds of different models to choose from. You shouldn’t automatically choose the cheapest or best rated garbage disposal. You need to find the one that is right for your unique needs.
If your garbage disposal is making a clicking or rattling sound, there may be some food particles that will not grind up inside. Remove power from disposer, reach into the sink hole with a pair of tongs and remove anything that is still down in the disposer. Test your disposer to be sure the noise is gone. If not continue troubleshooting your disposer issue (see below).
Garbage Disposal Replacement