You can certainly add salt if desired. Unless you have a salt water chlorine generator (SWCG), adding salt won't do anything except perhaps change the feel of the water. There's no other benefit to adding salt. Pool School suggests adding 2000 ppm salt to start if you don't have a SWCG but want to add it for feel. Use PoolMath to figure out the amount needed to add 2000 ppm.
And learn from my mistake, do it in steps. for instance if you want to get to 2000ppm, use poolmath and add the required salt to get to 1000ppm first. Retest to see what it actually is. Likely its above 1000ppm as mine was. Work the math and figure how much it takes you to get to 2000 after that initial add.
Moral of the story, dont try to go from 0-2000 in one add, you will likely overshoot it