It's not as easy as people make it out to be.
The simple truth is that you cannot just simply cut out some people out of your live. No, it's not that easy.
You will have to stay 'friends' with certain "fake" people, because you go to the same school, work at the same office or w/e.
But you can start talking less to them, to distance yourself.
Making new friends is also naaaawt easy.
You do not just walk to someone and ask them if they wanna be friends with you.
((I can't really give you advice on how to make friends tho, sorry.))