Learn to Ollie
There are many many good resources on you tube to help you learn to ollie. I have posted a few link below to help you.
https://youtu.be/QkeOAcj8Y5k
https://youtu.be/3Vrj4NxZF_c
https://youtu.be/knsEiranQd4
My only additional suggestions to help you in your way is to remember sight, sound and feel:-
Watch
How are people doing them in your local skatepark. Who does highest ollies? Who does longest?
Can you imagine the movements in your mind’s eye?
What is the rhythm of good skaters pop and landing compared to yours?
Feel
can I feel my shoe laces dragging on board?
how slowly / quickly am I flicking lead foot?
Is my backfoot jumping off toes, ball of foot or heel (popping / snapping)?
Am I light footed or heavy footed?
Am I tense or relaxed?
Hear
Can you hear your shoelaces dragging up the grip tape?
Can you hear a clean snap of the tail?
What noise do good skater’s skateboards make compared to yours (the snap (pop), drag and landing).
What is the rhythm of good skaters pop and landing compared to yours?