With a TC of 3 and an FC of 0, you have 3ppm of combined. That would require enough chlorine to raise the FC to 30ppm. Plus whatever would be needed for shocking organics etc. Algae will take time to kill, and even then may need a chlorine or even an acid wash.
You need to post pool size and gallonage for anyone to suggest much. If it is a huge pool and water is in short supply you may to try and clean it up. If not a drain, wash and refill might be in order. Kind of depends on how bad it is too.
Dupont makes a non-chlorine product called Oxone. It tremendous stuff for killing combined chlorine. Try getting the pH in balance somewhat and then wack it with Oxone. Whoever sells it can make recommendations for dosage. Too much is NOT a good thing. Afterwards you can try the chlorine again for a good shock and then work on the residual.