Difficulty adding custom emojis into server channel names and role names

Hello, 

I'm new to making servers and I need some help concerning emojis and putting them into channel names and role names. 

I've been in a number of servers where I've seen they've got emojis. When I looked up how it's done on the net, I just saw that people would copy and then paste the emoji into the channel name / role name and etc. 
I tried doing the same but it just came up with letters of the name of the emoji instead of the emoji itself. 

I saw something to do with Unicode somewhere, so I tried to find the unicodes of the emojis I wanted to use but there was just a bunch of numbers and they'd also just get pasted plainly. 

While I'm here, I wanted to ask, can you only use animated emojis with nitro? 

Thank you for any help.