A Series of Guidelines Taken From Surah Al-Fatihah

Tawhid: Tawhid is the core idea of Islamic monotheism, confirming faith in Allah's oneness. It includes the belief in Allah's uniqueness, singularity, and absolute sovereignty in His lordship, titles, and qualities, as well as His right to be worshiped alone. Tawhid is a very basic concept of Islam which is the backbone of the Muslim religion
Minor Shirk: refers to acts or ideas that include associating partners with Allah but do not rise to the level of blatant polytheism. It can involve activities such as flaunting one's worship, seeking favors from objects or others in a way that jeopardizes Tawhid, or an excessive connection to material riches that leads to a neglect of one's relationship with Allah.

Major Shirk: Major Shirk is the most serious kind of polytheism, in which a person ascribes partners to Allah in His sole divine characteristics or adoration. It entails identifying others with Allah in adoration, supplication, or imbuing created beings with divine traits. Major Shirk is a serious transgression that undermines the foundation of Tawhid.

It’s incumbent for the Muslim to be concerned with renewing his ʾĪmān (i.e., correct Islāmic faith) in the evening and the morning by pondering on the meaning of the statement of Tawḥīd lā ilāha illa Allāh since there’s no success except for the people of Tawḥīd. For it is the statement of Islām. So, the Muslim (Muwahhid) must learn about Tawḥīd, implement it, be aware of its position, reject Shirk which is the opposite of Tawḥīd, have a hatred for associating partners with Allāh as well as those who practice it. The Muslim must deem the one who commits major Shirk (knowingly) is a disbeliever of the true Islāmic Faith. The Muslim must also be aware of the position of Shirk.