To find out your number, add up all the numbers in your birth date until the last digit has one digit

For example: * You were born on December 17, 1996. You add the days, months and years of birth: 17 + 12 + 1996 = 2025. After that, you continue to add the numbers until you get a one-digit result: 2 + 0 + 2 + 5 = 9 The number 9 is the last number that will represent your date of birth.

I’m new, and I don’t know where to start and the blocks

A very good way to learn App Inventor or Kodular is to read the free Inventor’s Manual here in the AI2 free online eBook App Inventor 2 Book: Create Your Own Android Apps … the links are at the bottom of the Web page. The book ‘teaches’ users how to program with AI2 blocks.
There is a free programming course here Course In A Box and the aia files for the projects in the book are here: App Inventor 2 Book: Create Your Own Android Apps
How to do a lot of basic things with App Inventor are described here: How do you...? .

Also do the tutorials Tutorials for MIT App Inventor to learn the basics of App Inventor, then try something and follow the Top 5 Tips: How to learn App Inventor