Get User ID
$user_id = get_current_user_id();Get username
//For the current user
$current_user = wp_get_current_user();
$username = $current_user->user_login;
//For a different user
$selected_user = get_userdata($UserId);
$user_login = $selected_user->user_login;Get Avatar
HTML ready code to display it
$AvatarHtml = get_avatar($UserId, 32); //2nd argument is optional sizeAvatar URL
$AvatarUrl = get_avatar_url($UserId);Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.