Read the instructions for the BBQ. Weber bbqs should be used with the lid closed using the air vents to regulate temperature. They are brilliant in that way as you can get beautifully cooked food, not burnt, with minimal hassle.
If you dump loads of fuel on then use them open with all the vents open they will have a roaring high heat cos of the great airflow.
All I do with mine is fill my Weber starter with coals, light it, return 10m later when the coals are red hot, dump the fuel in the BBQ and cook for what always seems to be chuffin ages for the amount of coal I use. Open every few minutes to turn the food and adjust vents as necessary.
The instructions are really good, if you read them and follow them properly you’ll get great results and it’ll be a lot easier than you think.