HRT will do several things for you, just as for any other trans woman transitioning after adolescence. To me, I think the effects as largely preventative: preventing hair loss and development of more and more body hair. The main changes are breast growth (frustratingly slow, but it's there) and a dramatic change in sex drive. There are some other subtle changes -- somewhat different and less offensive b.o.; lither and less bulky (and generally weaker) muscles; a bit more subcutaneous fat; possibly a very slight difference in the quality of sound produced by my vocal folds, though that's hard to say; and some other subtle emotional changes (hard to distinguish from those caused by transitioning in general).
The main thing for me is to prevent any more damage from testosterone. If you're worried about hair loss, then HRT should probably be your priority.
As for FFS, I can't tell you. My process for making that decision is to try living full-time as a woman without FFS, and see how that goes. I've found it goes very well -- it's a huge improvement over living as a guy -- but I still want FFS. Others know either that they will want FFS, or that they won't, but if you're asking, I'm guessing you're like me. I could comment on your photos, but I think you know your face better than I do, and you know how you want to look. I would encourage you to see how well you can present as a woman now. Come out to some girl friends, and let them help you find looks that work for you. As you live into a female role, you'll find some things comfortable and some uncomfortable. You'll learn what aspects of your presentation matter to you. There's just no substitute.
But if you think you might want FFS in the future, then just assume that you will, at least for financial purposes: Start saving now. The worst that can happen is that you'll decide you'd rather blow the money on a wild weekend in Vegas ... or a Himalayan expedition ... or a Honda Civic -- whatever you want.
