I have found myself a really nice scheme of a buzzer that is controled by the IR led and photodiode by I want to upgrade it so it can be used for controlling a servo. What I have in mind is that when there is no object the servo whould stand still and when object comes by it will go to 90 degrees, wait for 5 sec and go back to 0 position. I just want to know is that possible for an Arduino starter and where should I look for help. Thanks.
Yes that is possible.
Start by googling for the two halves of your project separately. Find a project, example or tutorial which controls a servo. Get it working. Understand it. Then find one which deals with a sensor similar to the one you want to use, get it working, understand it.
Then you'll have everything you need to get your project up and running.
The convenience of the Arduio development paradigm is that most common hardware projects have been abstracted by software libraries to simple software interfaces. This is the case for controlling common servos motors.
If you find it sufficient, use the Arduino servo library to control servo motors. There are only 6 method to understand and in most cases you only need 2 or 3 of them. This example appears to satisfy your requirements for a sweeping servo.