Tell us what’s happening:
I have a problem with this section
2. The height of the welcome section should be equal to the height of the viewport.
and I dont understang why the icone gmail github and likedin is not visible
Codepen provides the boilerplate for you. It only expects the code you’d put within the body element in HTML. (No need to include the body tags). For anything you want to add to the <head> element click on the ‘Settings’ button, then HTML and add it into the ‘Stuff for <head>’ box.
One of the things to link to/call is Font Awesome since you want to use their icons.