Islam is based on 6 core beliefs:

Allah as the creator of the heavens and the Earth.
Prophet Muhammad as the final messenger from a line of previous messengers and propehts
Quran as the Holy Book sent by God for all mankind
Angels as beings of light
Predestination (Qadr) that all things happen by the will of God
Death as the ending of our life on Earth
Day of Judgement (Qiyamah) as the Last Day where God will judge all mankind
Afterlife where we will be sent to live in either Heaven (Jannah) or Hell (Jahannam)

29 Articles
Timeline of the Prophet’s Life
Belief in Prophet Muhammad
Resources to read, hear and understand the Quran
Brief history of the Quran
Overview of the Quran
The 99 names of Allah
Overview of belief in Allah
Beliefs Overview: The Six Articles of Faith