If you like to design Twitter emoticons, install Twitter Color Emoji Font:
sudo apt-add-repository ppa: eosrei / fonts
sudo apt-get update
sudo apt-get install fonts-twemoji-svginot
The best way to enter emoji mostly depends on your desktop environment. The best solution is to use EmojiOne Picker applet for Ubuntu.
This program will add an emoji applet to the taskbar or desktop control panel so you can easily search, copy and paste emoji.
Although designed specifically for Ubuntu and Unity desktops, this emoji also works on other distributions and some DEs like GNOME, KDE Plasma, MATE, XFCE, Pantheon and Cinnamon.
You can see the installation instructions for distributions on the Github page.
Once installed, run the program from the application launcher on your computer. The picker applet will be added to your system tray.
To use the picker, you just need to select the emoticon from the drop-down menu to copy it to the clipboard and paste it into the place you want.
These are all steps to help emoji display on Linux, hopefully this article will be helpful to you.