@Erdeta   
Not sure what OS or browser you’re on, but in Win+Chrome (and I think also Mac+Chrome) you can right click in the text edit area of any miro board object and add emoji. 

https://www.theverge.com/2018/4/6/17206312/google-chrome-emoji-desktop-shortcut-right-click

@Erdeta ,

You can set your avatar in the “Account Settings” option which is at the bottom of the board settings menu.

For emoticons/emojis, two options are:

1. Use your browser right mouse button popup menu to add them to a text box or a sticky note (e.g. in Google Chrome, the option is named “Emoji”)
2. Use the IconFinder app and search for “Emoji” - there are a lot available…