how can i install android in virtualbox?

https://www.android-x86.org/download > may be it works for you

Yep. And check this.
https://www.osboxes.org/android-x86/

systemctl start breached

Have a look a GenyMotion bro! It uses Virtualbox but is very nice when it comes to Android

Genymotion is really cool

I suggest using anbox https://anbox.io (android in a box) which runs natively on GNU/Linux alternatively you could run it in a docker container on any OS you want.
This provides much better performance than any other solution I tried such as nox/bluestacks/android studio etc

Yep. And check this. https://www.osboxes.org/android-x86/

Slightly different from installing a normal operating system can help with custom

Android x86 or something like Bliss OS/Remix OS which are are more desktop friendly version of Android X86

you can also check waydroid on linux ,it gives good performance