2001 Toyota Camry engine

A few years ago I purchased a new engine for my car, I was taken on the deal and paid much more than I should have. I only drove the care perhaps 5,000 mile since then, the car has been sitting in my drive way for years 3 or more. When I tried to drive the car I was told that the spark plugs needed to be replaced. I heard a sound like something dropped inside the engine when the guy went to change the spark plugs. I paid 200 for new sparks plugs left town for a week, while I was gone my husband says he also paid someone to replace the spark plugs, the car turns on, however, whenever you apply pressure to pedal you hear a raddling in the engine, therefore, I have not driven the car so as to not cause damage, I know the car needs a new air conditioner, any suggestions I really need a second car bad but my husband is no help at all.