Notes on Sears-brand water softeners. I've owned a few. They look a little different, but they work pretty much the same way.
When salt pellets are added, it's a requirement that the salt level be set manually using the Select button, then the up- or down arrow to select a setting between 0 and 10. Afterward, the unit thinks it knows how much salt is left. When the level reaches 2, the display begins to flash so that passers-by notice and make a mental note to buy more salt.
Pressing the Select button multiple times gets you to the time-of-day-set, recharge-time, water-hardness, etc. menus. I set the time of day and recharge times when needed, but I've never mucked with water hardness—too geeky to do that in my book.
To initiate regeneration, either after recharging the salt pellets or really any time you want, just press the button on the left of the Select button (see above). To initiate immediate regeneration, press and hold this button until you hear it kick off. This action is common to all Sears models I've owned. (On the units at both my homes, this is the button at the lower left.)
When you've left the unit un-by-passed to run without telling it about the salt level, the resin beads will be "worn out" and it will take a number of regeneration cycles to get things working the way they should. This usually happens as a result of procrastinating the purchase of salt pellets.
Even though the controls are older (for the one at the left, above), more sophisticated and don't look like [the one on the right, above], they do work this way.