when you turn the key on, to the first detent, all the lights on the dash should go on. This allows you to check that they work. When the engine starts, they should all go out.
If you have the owners manual, it will show the lights on the dash and what each actually means. If you don’t you can download one from the internet.
I’d restore the clamps to where they were, and take it back to the place you bought it.
For future reference, once a car seriously overheats, as your car did, the engine is probably toast.
Also for future reference, never buy a used car unless: 1. you have it checked over by your mechanic. and 2. you have put aside money for repairs, because it will need repairs. The cheaper the selling price, the more money needed for repairs.