You can become a mormon (or as we refer to it - being baptized a member of the Church of Jesus Christ of Latter-Day Saints) any time you want - at any age or time of the year. It is a very big and important decision. For someone your age - the church requires that anyone requesting to get baptized that they need permission from their parents/guardians. 
 
To start things off I would encourage you to contact the missionaries of our church. If that is not workable - then talk to someone at school who is mormon. They will be happy to talk to you about it. Or you could just start right here at www.mormon.org. 
 
Although you can become a mormon at some time in the future - people who do join almost always say that they wish they would have found it sooner or joined sooner than they did. But this is a personal decision that you will have to make for yourself. 
 
If you have further questions - don't be afraid to ask.

My husband and I have been members for over 12 years now and my husband had major obsticles to overcome. He has come a incredible way but because of insecurities that still hold him back, he is not ready for the stress of holding such a sacred Priesthood and I don't want him to accept such a responsiblilty before he absolutely feels he is ready for himself and not to receive it just to seal us together. I feel it would be a great burden releaser for him it we would be able to be sealed first and be able to accept that in his right time. I know when we do work for our ancestors as far as I am aware the men are not receiving the Priesthood to be sealed together. Thank you for you time in this matter. Of course I will accept Heavenly Fathers will in this matter and wait as long as I need for my husband to be ready.