Free memory of the phone

i am using a lot of tiny data base eand a lot of variable and i think than the memory of my phone is full

How can i have more memory or how can i chek how may memory i have and how many i am using and how many memory still free


Perhaps Settings>Device maintenance depending on your Android version.

Use Taifun's File extension: App Inventor Extensions: File | Pura Vida Apps


How much is a lot?
Variables are in Ram, not in file storage.