Salt dissolves pretty quickly, but you should wait for at least one complete water turn over cycle, the longer the better.

Adding salt to the recomended levels should not make your water cloudy. Can you post a full set of test numbers, including ppm salt?

How big is your pool? You can add liquid bleach to keep the water clean until you're sure the SWC is working as it should.

You'll want either a salt test kit (drops) or test strips (the salt strips are reported to be accurate and repeatable). You may need to calibrate your SWC after you get an actual reading from your water. I know mine was initially off by about 400 ppm. Now it stays within 50-100 ppm, which is good enough for me.