@BaruleK So, you're dealer is right, you don;t know what you're doing. Now that we've cleared that up... LOL
Like others have said, 45 minutes is too long to wait..Your coals are dying the minute they are lit.
Here's what I do.. Fill the chimney half way. Light it up.. Then put some unlit in the bottom of your baskets..
After about 5 minutes and the lit is going strong, pour it over the 2 baskets. Nice and even..
Wait a few more minutes and then put your lid on.
Do you have a grill thermometer? It helps to know how hot your grill is, but its not really necessary..
Depending on what your cooking, you can adjust your bottom vents to adjust the temp.
Just don't expect to have it change very rapidly.
Regulating temps and playing with fire is an art that requires some practice.
Have you read the Weber manual? Believe it or not, they give lots of good tips.
Depending on what temp you are cooking at, maintaining it is fairly easy..
My best advice is to start simple and Practice as often as you can.
Before you know it, you'll be burning food with the best of us.
Enjoy!