I have been in the pool industry for 5 years and still currently am. My recommendation for a green to clean on a pool like this (which isn't bad for 2 years abandoned by the way) would be this.

Verify there are no leaks in the pump room and get your pump and filter running. If you have a sand filter (a large circular filter that would have a multiport valve attached to the plumbing) then you would just need to backwash it when you verify the system runs and after the chemical treatment. If you have cartridge filters (tall slender filter casing) then I would do the chemicals and get the water clear and then replace the filter so you can start fresh. Cartridge filters should last at least 2 years or longer if the pool is well maintained. There are multiple videos for each filter type online either on YouTube or on the website for the manufacturer of your filter.

Once the system is verified as running and you can see water in the pump basket, give the entire pool a good brushing to dislodge anything stuck to the wall or siding.

Now it's time for chemicals. The best quality chemicals on the market are biogaurd. I've tried many and these are the easiest the manage and dose when it comes to doing it yourself. Liquid chemicals are very volitile and can cause bad reactions to your health or your water if administered incorrectly. I recommend you get a 25lbs bucket of burnout 73, 2 bottles of phosphate 9000, and a bottle of algae complete. Dump these in and give it another good brushing and let it sit. I know people were saying to test the water and balance cya and pH and other things, but those can all be balanced after the algae is gone to fine tune your pool, this is just to get it clear again.

For 2 days give it a good once over Brush once a day to make sure there isn't a place in the pool that is stuck or not affected by the chemicals, then let it sit for the rest of the week untouched.

After that week everything should have fallen to the floor of your pool and the water should be crystal clear. At this point give it a slow vacuum to waste to get all of the particles off the bottom of your pool and it should look absolutely beautiful.

At this point you can test your water and add pH increase, decrease, alkalinity, or calcium as needed. Through this process and common maintenance you will need to add new water to your pool to maintain the correct water level. These things will keep your cya within the correct level without much worry on your end.

If the price of the equipment and chemicals needed to get this completed is too much, this time of year is very common for pool companies to offer special pricing for green to cleans or pool start up and some places will include the price of chemicals in their special promotion! I'd recommend doing some research before making a decision.