Help ID-ing white “worm” on rock?

[Uzair Aiman]

I did not notice that. It does look like Aiptasia (the thing behind the white tube worms/normal worms).
There are different species of peppermint shrimp, and some are really good with eating small Aiptasia (but its not guaranteed).
Depending on the type of rock you have and how strong or brittle it is you may be able to chip off a small rock piece under the anemone (to ensure you get the foot off without leaving anything behind).
I've never had Aiptasia, so I cannot give good advice. I hope you can solve the issue

Hmm.. Ill look into the brittleness of the rock. But for now, I can see that theres an aiptasia on the sand bed, how should I tackle that? Im trying my best to refrain from buying any products first and try to remove them manually/ with glue.

 

[Tired]

Just stick your gloved hand or tongs in there and pull out the aiptasia and whatever it's attached to. Chuck it in the trash. Voila.

Aiptasia-killing products aren't bad to use. They're put directly on the aiptasia, so won't hurt anything else. But when you only have one or two aiptasia, the easiest thing to do is just glue 'em.