Learn flute could take at least 2 years to get all techniques done. I always suggest to student no matter what instrument or new skill you want to finally get to a certain level, find a good teacher at the very begging.
A "GOOD" teacher means someone who has great experiences on his job. Learn from her/him, it will effectively speed up your learning process and get what you want very fast.
Especially when your teacher has a lot of experiences to share with you, then she/he will give you a good idea / knowledge / useful skill on your instrument.
Before you decide to learn by yourself (self-learning) or do any change, make sure you could follow at least one good teacher and learn from her/him in 6 months - 2 years.
Then You will certainly get what you want and use it practically on your future. SO LET'S GO!!