Before you start Android Studio installation check your RAM size capacity and system speed. The speed of your emulator depends on the RAM size. Go to Android Development site and download Android Studio setup. If you are a beginner use old android studio like 2.xxx version before you upgrade. Click on the download button to download the software.
After download click on the file to install Android Studio. Run the software as Administrator and click next.
Select the folder to install the android Studio, I advice you install it on :/C or Documents. And click next.
When the installation is complete click Finish to exit the installation window
Android Studio comes with a lot of other files and libraries. Give the software some times to download all the required libraries. This may take time depends on the speed of your internet and PC.
Once you see the image below then you are good to go.
Congratulations you have installed the Android studio successfully.
If you are using Windows Computer, then continue with this method.
If you are using Mac or Linux, then continue with this method.