I have just recently decided to have house plants for the very first time. The problem I'm experiencing is that there seems to be some sort of fruit fly or gnat problem, and there is mold on the outside of the terracotta planters that I'm using. There was salt build up at first but I rinsed the pots out...now there seems to be mold and some gnats. Is this something with the plants or should I be looking for something else?

Please help, i have NO idea what to do.