Not months. Do you have a finished costume? If no, you cant join until you do so.
If yes but it's not approved then you should contact your local garrison GML with five pictures ...more if costume has specific little things hidden in the whole s/he will need to see...and he will activate you. Presumably you picked five tk id numbers already.
If yes and you've been approved and have a tk id number and can find yourself in the member db on 501st.com then it's all finished.
Which of these applies?