pool

I bought the house at a great price but agreed to treat the pool myself. The owners told me that there is nothing wrong with the pump they just haven’t maintained it since the house went on market. Which has been about 6 months. The pool looks like there is algae, I can’t see the bottom… and there’s a gigantic dead frog in there… God knows what else. It’s just gross.

How do I fix this and turn it into a sparkling (and clean) pool? If you can give me steps that would be awesome thanks!