Newbie from Louisiana

HI! We recently purchased a Summer Waves Elite 18'x48" above ground pool. After a rough start with leveling the ground, draining the pool, and re-leveling the ground I think we are ready for water! I originally purchased a saltwater system to go with the original pump, however, I was recently talk out of the salt water by a pool store guy. My pool has a metal rims and legs and he thought salt water would eat it away over time. Then he tried to sell me a Flippin' Frog which I researched and I'm not sure that is the way to go either. This is how I found this forum. My pool is nearly half way filled as we speak and I need to know what my next step should be. Of course I am most concerned about the health effects of whichever method I chose on my 2 small children. I am open to any and all advice.
Thanks in advance!

Pool: Summer Waves Elite 18x48 purchased June 2016
Live in south Louisiana
Using city water from a hose pipe to fill