Naturally there will be obstacles in their way for them to overcome. Naturally also there is no guarantee they'll succeed. Did Scarlett O'Hara really succeed at the end of Gone with the Wind? I would say not. She did end on a note of hope though and for her, given all that happened in the novel/film, that was a success of a kind.
So what defines success then can vary. What a character's expectations are can vary. Being introverted or extroverted will make a huge difference as to how likely it is that character will succeed in their aims. (It's far too easy for those lacking in self confidence to give up far too soon). And what about those deep down wishes your characters won't confide to anyone? Most of us all have things we would like but never say out loud because it "would sound stupid" or those around us wouldn't understand why we would want that something and we have no wish to hurt them. Our characters should behave like that too.
What will a character sacrifice in terms of what they want because they care deeply for another? How does that torn sense of loyalties - between what they want and suppressing that to help someone else - affect that character? Does the "hidden want" come out in the end and what are the consequences?