What do these symbols mean? If found on stone or some structure found in the past or present. Do they depict an alien language or just lost knowledge.

Are they signs? Do they mean spaceships?

Ȯ ʘ Ѫ Ԕ ߶ ࿂ ᙼ #

Kalv == ཀལབ

Answer: Just characters from different languages in our world today, from different countries. Found in UTF-8 character tables.