Anatta-"Not Self” is the third fact of existence according to Buddhism.
Your “self” is not fat or skinny. Your "Self” is not pretty or ugly.
Your mind, your body, feelings, and organs do not represent a permanent entity called" the Self". They are temporary. When you remove everything from the components of the mind and body, nothing remains. It means that your individuality is a temporary formation, a coming together of various impermanent things. You hold them together out of desires and attachment. They are the glue.
The Buddha’s teaching points us away from looking for the self, or trying to understand or improve the self. Instead, pay attention to your fears, desires, ambitions, and clinging that motivate you trying to build self identity. Can you instead find the particular suffering that is connected with wanting to improve your “self"? Liberation entails releasing our suffering, not avoiding it, seeking relief from it or compensating for it.
Practice becomes very simple if we pay attention, carefully and non-reactively, to our suffering. If you simply watch your suffering and its cessation, you will see the grasping and you will see the possibility of genuine happiness that comes from releasing that grasping.