That last is good news.

Pool stores complicate stuff for two reasons: 1) to sell you lots more stuff 2) they have no idea what REALLY works and what does not.

You are going to need to follow some basics to get your pool clean, but first you will need to get us all these numbers:
FC
CC or TC
pH
T/A
CH
CYA

You've given us some of them. You can ask the pool store to test your water and get us those numbers and say something like "I just want to see how your advice is working" and DON'T BUY ANYTHING FROM THEM!

We have some sections on dealing with algae. You should read them.

You'll need to keep chlorine levels high, clean all the detritus from your pool, vacuum to waste once a day. Brush the walls and bottom once a day, and check and keep your chlorine up 2 to 3x / day.

You'll also need lots of POPP--Pool Owner Patience and Persistence.