How to get rid of echo and high pitched noises

[Siobhann5FCA]

Hi I have been looking at tutorials online but have yet to find one that talks about how to fix high pitched noises. I do not know how to explain it, but there is this weird fuzzy noise and this weird noise that continues after dialogue is finished. 

I also have tried to get rid of the echo but nothing has worked so far.

Please help me!!!