Not the best picture in the world but does indeed look like snails, more specifically, pond or bladder snails.
Very common and generally harmless in the aquarium.
Would have been highly likely they were indeed hitchhikers from being on plants.
These snails will help a little with algae and debris, part of the clean up crew if you like.
Snails will lay clear eggs in a clear jelly sac on just about any surface in the tank, glass, decor or plants and you’ll soon see baby snail going about.
Keep feeding livestock to a minimum, don’t specifically leave out food for the snails otherwise the population of these snails may get out of control.
If you do not want them then quickly take them out of the tank and hopefully they won’t have laid any eggs just yet.