Two Qs about Sept goal

Sept is my first month in SCS (yay!). Thinking about my 30 day goal and I have 2 questions:

–should it be something I want to sustain/achieve for 30 days or something that I will achieve by the end of 30 days?
–although focusing on overeating would be the obvious choice, i feel resistance over this and instead feel like I want to focus on building routines that support my wellbeing (which would include meal-planning etc which would impact weight but would include other nonrelated routines). Is focusing on building routines too vague?