Where can a fresh graduate in computer science get experience? all jobs require experience.?

try getting an internship, or getting a computer related job in a computer lab (ie not actual programming)work there for a year and apply to other jobs in the meantime with your newly fattened resume

A couple of things to consider:

1. The best way to get a job straight out of college is through a connection. Your parents, friends, relatives all know someone who works somewhere that has an IT department.
2. Not all jobs require experience. The job postings you see listed on Monster.com and other sites are describing their ideal candidate. An ideal candidate may have 5-7 yrs experience in languages x, y, and z, but the actual job will never require the use of language y. Don't get discouraged. Job postings are written like your resume. You probably don't have experience in half of the languages you have listed, but you have "touched" on them and know you could learn them quickly.
Computer science is the easiest discipline in the world to get experience. Just build some new, interesting, cool application and make it available on the Internet. Anyone who is hiring will be more impressed by that than anything else you can do.