Sounds like you don't have enough charcoal on the grill. I try to have at least two layers in my cooking area. I always add some more between when the starters are ready and when I want to cook.
Don't worry. After a decade or so you will have a good feel for how much charcoal you need to get the desired results. Until then, keep the pizza guy on speed dial.
You will make mistakes, you will learn from them.