having a boat will be a great step forward.
having a boat that is equipped,and prepared for the ocean will be the next step after that.
having a boat that is equipped ,prepared,provisioned,crewed and fueled up and ready to go is the last step.
i would start looking for crew somewhere between steps 2 and 3!
or about four -six weeks before planning to leave,generally i have found 2-3 months is about average for crew who stay onboard before they want to move on,some will leave after a week and a rough passage
,others will want to stay forever!
good luck on finding a boat!