Add class:
<form action="insert2.php">
    Name:<input type="text" name="classname">
    Room: <input type="text" name="room">
    <input type="submit">
</form>

Add Meeting:
<form action="insert1.php">
    <select name="classid">
       <!-- list of classes -->
    </select>
    Date:<input type="text" name="date">
    Time: <input type="text" name="time">
    <input type="submit">
</form>