If I understand correctly what you want achieve, this has been documented pretty well on SE sister sites:
Firstly assuming you have successfully installed Android studio, it needs the following files to successfully run an AVD:
- sdk tools
- build tools
- platform tools
- system-images
- sources etc
(You may download these separately as zipped files, but make sure to extract in the correct directory)
![enter image description here](https://i.stack.imgur.com/peGeU.png)
In case you haven't got Android studio (or standalone sdk manager) up and running, you may need to get started by following these posts on sister sites:
Stackoverflow: How to install Android SDK on Ubuntu?
AskUbuntu: Complete Installation Guide for Android SDK / ADT Bundle on Ubuntu
Unlike on Windows, you can simply access avd manager using command-line i.e open terminal ( CTRL + ALT + T) and type android avd
to open the Android Virtual Device Manager.
Configure your virtual device to suit your needs, click start and from here you can launch your AVD