Do I have to see a psychologist first? And what kind of psychologist do i need to see and how long before he or she puts me on HRT?

You should look for a therapist specializing in gender therapy.  They'll want to evaluate your mental state, and they'll want to make sure that you know all that HRT will entail; the SOC recommends 3 months, but it depends on the therapist.  The therapist will write a letter of referral to begin HRT; even PhD psychologists are not allowed to prescribe medication themselves.

Good Luck. 

You need to find a gender therapist that knows about GID.  They can then give you a letter of recommendation for HRT, after a few visits.  You then find an Endo that treats Transpeople and give them the letter.