Praise be to Allah, and may peace and blessings be upon the Messenger of Allah. To proceed:
Ahl al-Sunnah wa al-Jama‘ah believe that Allah Almighty is above all of His creation and has risen over His Throne in a manner befitting His Majesty, without asking how, likening Him to His creation, or denying His attributes.
Where was Allah before the creation of the Throne?
It is authentically reported that the Prophet ﷺ said:
“Allah was, and there was nothing before Him, and His Throne was over the water; then He created the heavens and the earth.”
Allah, Glorified be He, is the First. He existed before all created things, and there was nothing with Him. Then He created the Throne and the rest of creation, and He rose over His Throne as He has informed us in His Book.
Did Allah need the Throne?
No. Allah Almighty is completely independent of all His creation. The Throne and everything else are dependent upon Him. He is the One who created them, preserves them, and sustains them by His power, while He is in no need of anything from His creation.
Conclusion
Allah Almighty existed before the creation of the Throne and the heavens, and there was nothing of creation with Him. Then He created the Throne and rose over it in a manner befitting His Majesty, as stated in the Qur’an and Sunnah. Affirming Allah’s exaltedness and His rising over the Throne does not mean that He needs the Throne. Rather, He, Glorified be He, is completely independent of all creation.
And Allah knows best.