How do I know God is real?
Doubt is not the opposite of faith. Indifference is. If you are asking this seriously, you are closer than you think.
Something rather than nothing
The universe had a beginning, runs on laws precise enough to write down, and produced creatures who ask why. None of that proves God on its own; all of it sits more comfortably with Him than without Him.
The weight of right and wrong
Almost nobody actually lives as though cruelty were merely unfashionable. That stubborn sense of real good and real evil points somewhere beyond our preferences.
Test it honestly
Scripture repeatedly invites investigation rather than blind acceptance. Read one Gospel — John is a good start — and ask God plainly to show Himself if He is there.
What the Bible says
“For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead.”Romans 1:20 (KJV)
“And ye shall seek me, and find me, when ye shall search for me with all your heart.”Jeremiah 29:13 (KJV)
“Lord, I believe; help thou mine unbelief.”Mark 9:24 (KJV)
Bring the doubt itself. It is welcome here.