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
- sources etc
(You may download these separately as zipped files, but make sure to extract in the correct directory)
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