Adding the friendly Welcome message to your user talk page by using {{Welcome}} or {{subst:Welcome}} on most Wikimedia wikis, sometimes --~~~~ is needed addiitionally for signature. Like this:
Hello, GlobalWikiWelcome. Welcome to the Wikimedia Meta-Wiki! This website is for coordinating and discussing all Wikimedia projects. You may find it useful to read our policy page. If you are interested in doing translations, visit Meta:Babylon. You can also leave a note on Meta:Babel or Wikimedia Forum if you need help with something (please read the instructions at the top of the page before posting there). Also worthwhile acquainting yourself with the functions of global user pages. Happy editing!