.footerLinkedin a::before, .footerPhone a::before, .footerEmail a::before{
   font-family: "FontAwesome"; /* This is the correct font-family*/
    font-style: normal;
    font-weight: normal;
    font-size:18px;
  padding-right:12px;
}
.footerLinkedin a::before{
    content: "\f08c"; /* You should use \ and not /*/
}
.footerEmail a::before{
    content: "\f0e0"; /* You should use \ and not /*/
    padding-right:8px;
}
.footerPhone a::before{
    content: "\f095"; /* You should use \ and not /*/
}
.footerLinkedin a, .footerPhone a, .footerEmail a{
  font-weight:600;
}