Answer 1

Variable is a name that can store and save Values.
For example : It’s Like a box you call it toys and you store toys inside it.

Answer 2

Minimum age for SoloLearn is 13, but you may be permitted if you email [e-mail]

They have (because of laws for protecting children) to be sure that children may not be exposed to bad people. Sorry buddy, but maybe you can have an account that doesn't have messaging until you are 13?