Hi, i'm french and i learn your language.
can you tell me if my text is understandable for you and if you do not see spelling errors.
you.
hello every body!
it's perfect you're all at time !
i'm receiving you because mr atkins called me on my phone to tell me that he won't be present with us. he has a fever and headaches and he has to stay in his bed, he probably has a flu .
he apologize sincerely for his absence .
i reassure you, we're not alone.
so mr burden will replace him and we'll go together to the airport to welcome our french students .
mr burden can be late because he has to recover our bills of train and the official documents. i hope we won't miss the train.
so we wait him here quietly and patiently.

Hello, dear. For the most part, you're doing wonderfully. Some parts don't make a whole lot of sense, but it's getting along quite well.
I would recommend this revision, though:
Hello, everybody!
It's good that you're all on time!
I'm sending this out to tell you that Mr. Atkins called and said that he won't be here today. He has a fever and headaches, and is staying home, since he probably has the flu, but apologizes sincerely for his absence.
It's alright, though, because Mr. Burden will replace him, and we'll all go to the airport to welcome our French students.
He may be late, because he has to get our train tickets and official documents. I hope we won't miss the train.
So, we'll wait here quietly and patiently for him.

I'm not quite sure why you have something about missing the train in there, if it's just for conversation, or what, but that could possibly be left out, if you wish. Otherwise, you didn't spell anything wrong, it's all just grammar and word placement things.
I hope this helps!