@BillsomethingFirst off, no, you did not have to come off so aggressive. I appreciate you letting me know that the character is confusing, but a simple request for an explanation would have sufficed. I hope the following explanation helps.
This will be posted on the Original Post as well.
The character sheet serves multiple purposes, it informs me of who your character is and provides me with an idea of how you will play your character. It also provides a frame of reference for yourself and everyone else when interacting with your character. It also serves the very distinct purpose of allowing the other family members to have formed an opinion about your character. Yes, mystery is good and your character will of course develop, change, and grow, but remember that these siblings and parents all have known eachother for a very long time and will have already formed opinions about the other characters. Certain mysteries are possible, like sexual orientation, mental struggles, but for the most part your personality and behavior are things that will not be big mysteries. We need to know what our character will think of your character as this is an RP about a family.
Personality: is self explanatory, it is the general template by which your character operates. It informs their decisions and who they hang out with. It dictates how they approach people and life in general.
Behavior: goes into the minutia of day to day. How the character acts towards people. Does he lash out at his parents often. Does he do a lot of pranks? Does he get into fights a lot? Does he mistreat his siblings? Does he ignore authority? When his parents give a curfew, does he follow it or not. When you think about one of your family members, you think of their personality, but you can also think about the things they have done and how they act in front of people, that is their behavior.
Type: admittedly isn't as self explanatory as personality, which is why I tried to provide some examples. Is your character the adventurous type? Are they the loyal type? It's somewhat like describing characteristics, but it's not so much about traits so much as succinct terms that show how they move through life. Someone who is adventurous might like rock climbing, or solving mysteries. Someone who is loyal will defend their siblings, or their friends. It very importantly also provides the other players with an idea about your character and how our characters will interact with them.
Explanation of Type: is somewhat a replacement for history. You say your character is adventurous, now give examples or an explanation of how they are adventurous. My character likes to go rock climbing on the weekends. They love visiting new places. My character is rebellious - but not all rebels are the same. My character rebels against the idea of school. They don't shun authority exactly, but they don't think that school should be required. This helps us understand your character better and provides us with some ideas about whether our characters like to hang with yours and so on.
Likes: What does your character like? Music? Comedy? Travel?
Dislikes: What doesn't your character like?
Aspirations: What your character will be working towards in the long run. A life goal or a desire.
School Performance: This is important for the parents and for family members, again, to form an opinion. In some cases, like if your character is in college, this can say something like, "Chooses not to disclose this information to their family." But in high school, this option is obviously not available. School is an important aspect of being young. And again, it helps our characters be more informed about your character.
Plans: This describes what your character wants to do with their life in general. Their plans for the year, short term. How they plan to get to their goal, or how they will make the most of the move to the new place. Or maybe they plan to improve their grades or relationship with their siblings or parents. It also gives me an idea as to what you want out of this RP.
Remember that this is a family RP. They all know each other. We need to be able to have a very good foundation of who we are are and who our family is.