How To add social Media Plugin In Your Site (Blogger site, WordPress Site or any other site) You can add with following steps

1)    Add YouTube Subscribe Button :

i)      Fisrt Open this site - https://developers.google.com/youtube/youtube_subscribe_button

ii)    Login with your channel login id

iii)  Paste your channel Id or channel name

iv)  Copy Script tag from Code section

v)    Paste this tag in Blogger -> Laoyout -> Gadget ->Choose HTML/javscript and paste here.