Are they cone shaped like Malaysian Trumpet snails, or little spirals - Ramshorns, little oblong - Bladder aka Pond snails or something else???
You can check the shapes of these in a search and see which ones are closest.
For now manually remove them if you do not want them in your tank. If you can smash the shell and you are okay with that, you can feed them to fish most will eat them.
New to FW fish? First tank in a long time or EVER??? Need some info on keeping fish?
Start here - Aquarium Advice Article
FW Favorites right now Clown Loaches, any shrimp - SW Vase Red Mangroves