Prepare your self. You need Sailing skills Navigation skills and Mechanical skills.

The best way to get those skills is to sail on other peoples boats.

At this point you have a dream - be sure you want to pursue that dream by gaining experience.

Get some daysail experience, some overnighters if you can and then look at places like the SSCA discussion board under crew wanted for an ocean passage. After you have done that you have better knowledge to buy and equip wisely.