Hi Plix,
Welcome to Susan's place. There are lots of wonderful people here who will be happy to help with advice and support. There is also a great deal of information. I here you about wanting FFS before living full time, however it is expensive. The electrolysis or laser treatments to get rid of facial hair alone will cost between 10 and 20k.
Surgery will depend on how extensive you want to go. Thing is if you are already on HRT your body will start changing very soon. In fact since you are only 20 the effects will probably be quite profound long before you can complete FFS. Also the requirement to live full time is part of the transition process so I really don't see how you can avoid going out before FFS.
Many MtFs are overly concerned with passing as are FtMs but usually to a lesser degree. You might want to check out my post on "Owning the part" found in the "Coming Out" board. It might help you gain the confidence to start living as yourself.
I live full time as the woman that I am and I have not had FFS yet. For now my only plans are for beard removal, Which as I've already stated is an expensive proposition in and of itself. It is also quite painful. Just ask anyone here who has gone through it or is having it done. Now I might have a face lift after all is said and done but I think that will be pretty much it. Well that and a trachea shave to diminish the adams apple.
I don't know your particular situation or what you look like but if your 20 your face will probably feminise a great deal on it's own. Give the HRT a chance to do it's job before you start going under the knife.
I think transitioning begins with the acknowledgement to yourself of who you really are, as everything else procedes from there. Everybody is different. You could say your first day on treatment is your new birthday, so you might want to mark the day on your calendar.Anyway, there are lots of resources here so fix yourself a cup of tea or other relaxing beverage, sit down, take your shoes off and set a spell. You are among friends.
If you haven't read the site rules yet please make sure you do. Also for lots of really good info check out the Wiki board.
Good Journey,
Cassie