Aspirin works as a painkiller, but it is not appropriate for regular ingestion as self-medication if you don't know what you're doing. It can be used sparsely for relieving pain+fever or pain+inflammation (IF the inflammation actually needs to be treated).

Paracetamol is a much safer option with almost no side effects, as long as you stick to the daily limits.

Plugging in this video (in french) from a doctor about various painkillers: https://www.youtube.com/watch?v=qCg6if1KZvQ