If u have fine filters for the kreepy krauly use them - they will assist in the fight.
It is like having a roving cartridge filtering in your pool - which is finer filtration than your sand filter. Clean the filters often.
Those drain covers have voids beneath them that can hold funky stuff (often a bowl type situation with the pipe in the middle)
Yours look like they have screws that hold them in place (Some just untwist kinda like a smoke detector).
Wearing something weighted can assist in being able to get down there & remove them & scrub out the crud.
Don’t do this alone- Be sure u have an assistant at the ready incase u need help.
Alternatively - you can use a piece of pvc to reach them from outside the pool & get some concentrated liquid chlorine in there. Be sure to have them running some & brush the area well. U don’t wanna bleach your liner.
An auto fill is a water line plumbed to your pool that keeps your water at a certain level. If u need to top up your pool manually with the hose then u probably don’t have one.
Most are similar to this

Some pools also have an overflow drain that can get funky (sometimes above the waterline somewhere around the coping). I don’t see one from the pics but u may have one in your skimmer. If u scrubbed around in there u are good to go.
Maintaining Slam level for your cya as often as possible is crucial.
If u wish - You can use your swg to help while u are away just be sure it’s off for any
Overnight Chlorine Loss Test
At the beginning of a slam running the swg can be a bit fruitless so it is suggested to turn it off - but near the end when the fc drops aren’t as great it can be useful.
Ps- your steps are likely fiberglass.
Be sure to scrub any seams around them.