First things first: After installing Ubuntu 16.04

Install Google Chrome

You've met some troubles, right?
Follow these instructions

Install Sinhala Input - Wijesekara

Follow these instructions

Install LAMP stack

1. Install Apache
   

   sudo apt-get install apache2

2. Install MySQL
   

   sudo apt-get install mysql-server

3. Install PHP
   

   sudo apt-get install php5.6 libapache2-mod-php5.6

4. Restart Server
   

   sudo /etc/init.d/apache2 restart

5. Check Apache
   Open a web browser and navigate to http://localhost/. You should see a message saying It works!
   
6. Check PHP
   

   php -r 'echo "\n\nYour PHP installation is working fine.\n\n\n";'

Install phpmyadmin

This could be done at once at first. I had to see alternative methods other than install it manually. So this is the way.