Firstly you will have to decide that in which sector you are interested to work and in which type of company you want to make your career.
Make a LinkedIn account. Add the HRs from the companies you wish to work for to your LinkedIn account.
You can find their email ids in their profiles once you added them into your account.
Email id mentioned on the careers page of every company’s website. They are actually the id’s of HR department. Just Google the company’s website and get into it.