I am new to zoho creator.I am looking to build an app for Athlete registration for Gymnastic Competition and then use athletes to Apply for game participation in different competition and age  categories 

Different Age Categories are:

1) Age 11 or below

2)Age above 11 below 14

3) Age above 14 below 17

4) Age Above 17

Different Competion Categories Are:

1) Individual Men

2)Individual Women

3) Mix Pair (1 male and 1 female)

4) Trio ( Team of three not gender Specific) 

I Have managed to get User Registration  Form where I am able to get the athletes registered with their information

I have created another form called "Apply to participate"

Where I have added three Lookup Fields in dropdown

1) Add User (List of all users Added in User Registration form)

2) Select Age Category (with all above mentioned age categories)

3)Select Competition Category( with all above mentioned Competition Categories)

Now I want to apply necessary validation to this form before submitting 

1) user age should match applied age category

2)mix pair - one male and one female

3)Trio -not gender specific

I have no scripting knowledge. It would be of great help if anybody can help me out in building this app