Here is a corrected version of your sentence with simple explanations:
Original sentence:
For those of our friends who did not have a chance to join us at the fair and see our new titles firsthand, you are most welcome at our stand at the upcoming fair.
Corrected sentence:
For those of our friends who did not have a chance to join us at the fair and see our new titles firsthand, you are very welcome to visit our stand at the upcoming fair.
Explanation:
- "You are most welcome" is correct, but "you are very welcome" sounds friendlier and is more common.
- Instead of saying "at our stand," saying "to visit our stand" makes it clearer that you are inviting someone to come and see you.
- The rest of the sentence is grammatically correct and clear.
So the corrected and friendly sentence is:
"For those of our friends who did not have a chance to join us at the fair and see our new titles firsthand, you are very welcome to visit our stand at the upcoming fair."