Option 4 (not listed) is to spend 2 or three hours reading the hundreds of similar stories found in these forums from this year and past years. This definitely goes hand in hand with Pool Owner Patience (POP) It does take time to absorb, comprehend and utilize the very helpful information found here but time spent doing that will answer most of your "What is..." questions and many of your "how do I...." questions.

I don't mean to sound like a nit but a little knowledge and prep goes a long way towards confidence in approach and the information found on these pages is GOLD that can and will help you.

Avoid asking pool store employees for advice on what to do and stay the course with the methods and approaches listed and talked about here. The short money you spend on a test kit now will save money many times over going forward. It all seems complicated at first but after understanding a few concepts it's really not as hard as it looks or sounds. (same as fly fishing really)

Follow Ben's advice listed above and be patient. Your Pool took all winter to get this way so it's going to take a while to get sparkling and clean. This means continuing with the chlorine (bleach) as advised, vacuuming when necessary and continuous pump/filter operation for as many as 2-4 weeks.

Two years ago I was in the same position you are now. We bought a new house in the fall that came with a pool and I opened to a green mess in the spring. Thankfully I had found TPF during the winter and was somewhat prepared to deal with it. In three weeks, using only a quart of Poly quat algaecide, 20 or so gallons of 6% bleach and 3-5 hours of leaf raking and vacuuming I was good to go.

As for winterization...I think the pool industry has a deep interest in convincing the public that winterization requires much more effort and chemicals than you really need. . When I closed last year I shocked my pool with a few gallons of chlorine and then added a half a quart of of poly quat algeacide for preventitive measures and then put a cover on. This year I opened a month earlier, in Mid April, than last year and my water was crystal clear and good to go. After hooking up my filter and pump the pool was ready for swimmers in just a day or two. I'm convinced the early open date (and subsequent cool water temp) was largely responsible for the clear water and ease of opening. The only challenge really was to keep up with the spring detritus from the trees in my yard as they blossomed. 10 minutes of skimming a day and 30 minutes of vacuuming a week has taken care of that though.

Kind regards and good luck.