@Preety_India First of all, all the kindness and help you give to others you should do out of yourself not to get anything in return. You make peace with the idea of helping someone a lot and them not doing anything back for you. View helping people like you view giving money to the homeless guy, you help him because you can and you enjoy it, not because you expect the homeless man to do anything for you. Now some more practical advice
Friends- personally i am a very intuitive guy so i can tell trustworthy people just by the way they act, facial expressions, gestures etc. Also having a good memory and remembering what people do and say can help as it helps you spot out inconsistencies like lies for eg. Also try to have self respect and boundaries so people wont take advantage of you. Develop yourself to be an interesting, likable and cool person so people wanna be near you. Do not get overly attached to people.
Partners- Pick people based on kindness, caring, honesty etc not based on assertiveness, detachment, confidence and charm. If they have the latter qualities that is a bonus but not the core.
Aquitancies- No reason to even give a shit about people you are not even close with to be honest.