Updating from MYSQL to MYSQLI

So as MYSQL is deprecated and eveyone keeps telling me to update, I thought it was about time I did.

But as I'm not used to mysqli_*, it seems alien to me. And it's not a simple edit when I have a whole site coded in Mysql.

So I'm wondering: How would I transform the below code into Mysqli? Just to give me and anyone else a good starting point when dealing with querying the database.

$sql_follows="SELECT * FROM friends WHERE user1_id=".$_SESSION['id']." AND status=2 OR user2_id=".$_SESSION['id']." AND status=2";
$query_follows=mysql_query($sql_follows) or die("Error finding friendships");
if($query_follows>0){
}

EDIT: On reading up and editing my whole site the above code converted to MYSQLI_ would go something like this..

 $Your_SQL_query_variable= mysqli_query($connectionvariable,"SELECT * FROM friends WHERE user1_id=".$_SESSION['id']." AND status=2 OR user2_id=".$_SESSION['id']." AND status=2")) {
        printf("Error: %s\n", $mysqli->error);
    }