How will I know my application's open? I filled mine out when it first opened and haven't heard anything back, or will I need to see the portal.
Your full candidate kit will open in the summertime. I would advise now that you have completed your candidate questionnaire to continue to seek high GPA in AP/honors/IB courses, improve standardized test scores, and continue to seek leadership positions (varsity team captain, achieve eagle scout, youth group leader, boys state, class president, etc.). In addition to all of this you should contact your FFR try and arrange a phone call or just correspond via email if that's best for him. Introduce yourself, explain why you want to go to West Point and how serious you are about it, ask how you can improve your file and what your weakest points are, he can provide solid info before your candidate kit is opened up. In addition, start researching into your nomination opportunities, senators, congressman, any service connected nominations you are eligible for (you can view these under the nominations tab of your portal) see what they require (e.i. a letter of why you want a nomination, letters of recommendation, high school transcripts, test scores, an essay, a resume, etc.). Lastly, do a bunch of research into the academy on the website, look at the different sports, majors/minors, programs, military summer development schools, different posts, different branches you can go, etc. Learn about these to not only gain a better understanding about the academy, but also this is the kind of stuff you will be asked during interviews (FFR/congressional), they want to see you are prepared and did your own research instead of just willy nilly decided you wanted to go to West Point (that was me last year and I got rejected). Read old threads here on SAF, they are full of great and valuable info. One last bit of advice you may want to do is read some books like "The West Point Candidate Book", by Sue Ross and "Absolutely American", by David Lipsky.
Good luck man, and remember only worry about, and do what is in your control!