A complete armature i am but i have a plan to make an app that work like a private assistant so what language i need to learn

Answer 1

Do you mean a pvt. assistant like Siri or Alexa ??
If you are talking about that, that's close to impossible for a single person to build it. You need a team of like 20 engineers to make perfect within 1-2 years.
It's hard. You can see why only 4 of them exist in the entire word ->> Siri, Google Assistant, Watson and Alexa.

Answer 2

Python would be the easiest and most powerful language for this purpose.
https://www.sololearn.com/discuss/821134/?ref=app

But if you want to create an android app, you need to learn Java/Kotlin.
https://www.sololearn.com/discuss/580291/?ref=app
https://www.sololearn.com/discuss/823843/?ref=app
https://www.sololearn.com/discuss/823823/?ref=app