This is obviously something you ought to talk over with a gender therapist, but to speak generally on the subject, most people who transition to female have a deeply-seated internal feminine identity. This often manifests from a very young age and can be pervasive - you might love girly cartoons, always role-play as females, gravitate towards girly clothing or behaviours without even being aware of it, or otherwise have a sense that something is not right and it's because you "wish you were" a girl (in fact, in this case, one already always has been a girl, if only inside, and the realization of this inner truth can be likened to a kind of euphoric awakening process).
On the other side of the fence, are those who will dress up as Jasmine and insist that they're Aladdin, so to say. If it's a strictly sexual or artistic matter and you're otherwise comfortable with labels like "he/him" (maybe outside of some escapades), your birth name, the idea of having kids, and basically want everything else to stay the way it is now, you could simply be a crossdresser - in that case, don't even worry about the transgender label because it has to do with identity rather than just behavioral inclinations. There are people who never transition and are still transgender, and then there's my cousin dragging it up almost nonstop who is still perfectly happy as a gay man.
You can be a straight man and into drag / fetishisms. That's completely normal. In fact the main distinction gender therapists traditionally tried to make early-on using the DSM was between transvestic fetishism and full-blown transsexuality. Of course, you're able to live your life on your own terms, and if you wanted to do anything "transitional" so to say I'm pretty sure you'd be able to find medical professionals who would help you.
A good rule of thumb, though? Go for 10 hours of facial electrolysis to remove any facial hair you might have and see if you're up for more. Transitioning is brutal, intense, life-altering, and 100% completely worth it - if it's right for you.