Queries:

Make a select query with a calculated field for age,  to list only guests between 20 and 40 years of age! Make sure to enter a range of ages in your table so you have something to display.

Make a Parameter query that allows the user to choose which birth month to display. So when the user is  prompted for a birth month, they might type in 3, for March, and only the records which have a Date of Birth in March, will display.

Make an Update Query that will add the phrase "Free Champagne for this Preferred Guest" to the Comments field, but only if the guest stays for 8 days or more.