To trust no one.
To understand, and accept that on a base level, we are alone in this world.
To do, and accomplish things that are to your own benefit first.
Dont feel guilt or shame when you reject other peoples offers, work against someone else's wishes, or make them do something they don't want to. Within reason, you should always operate to your mission and goals.
Do not help someone too much, for they may begin to resent you. The fact that you have more than them, and that you are above them causes this. Instead, help a little, and don't get top involved in their problems.
Surprisingly, friends are more likely to sabotage you. Always analyse and decipher how they truly feel about you. A true friend in this life is rare.
Accept, recognise, and learn other peoples manipulative and machiavellian ways. You will never be conned, tricked, or deceived. It will also help you understand how to be more successful in relationships, the workplace, business, and social situations. Of course, you don't want to go too far that it conflicts with your morals.