How can I get started with contribution?

[Pradevel]

Have a look here

How do I get started with contribution?

Welcome @Ujjwal_Mishra, The best way to get started would be to set up your development environment and build the App Inventor sources as documented here. You'll need a copy of OpenJDK 8, which you can get here. Once you have built and run App Inventor locally, take a look at the issues marked help wanted on GitHub. These are usually good starter projects to get you situated in the code base. Feel free to ask any questions in the open source category on this forum. Cheers, Evan