My son is almost 4 years old and he still throws tantrums, crying and screaming hysterically when he doesnt get what he wants or is made to wait for something. Is this normal at his age? How do i make him learn to wait?

Yes it's perfectly normal for his age. They are at a age of expressing themselves yet they still don't understand time management or patience or rejection. Take a deep breath and slowly talk and explain to him. It takes multiple times and effort but it will work out one day