vauxhall zafira gsi, when l start the engine the alarm goes off,and the starting motor is making a funny sound under staring,please please please can anyone help??????

Your starter motors brushes are most probably worn out. You can either get the starter motor refurbished or fit a new one.
Your Alarm is being activated due to the battery voltage dropping below 10v whilst trying to start as the motor has to work harder with worn brushes resulting in a increased current drain.

The most likely fault with the Zafira alarm is the actual siren (power sounder) itself faulty. It will need to be plugged in to check for self test failure. It is a very common fault but relatively cheap to replace.

As far as the starter motor goes, without hearing it l could not say. Get them both looked at together.