Being positive can be hard sometimes, and surrounding yourself with negative people doesn't make it any easier.
The Law Of Attraction is the belief that positivity attracts positivity and negativity attracts negativity. If you focus on positive thoughts you will receive positive results, and vice versa. For example, if you walk into a classroom you can tell if the teacher is in a bad mood or not. If they are, you instantly feel worse than you did before, the lesson isn't as fun, and there's a lot of tension in the room. However, if the teacher is in a good mood you feel happy and slightly more excited for the lesson.
By someone being in a bad mood, it can lower yours. I know from past experiences that this is true and I don't like it at all. When I'm around people I try to be happier. That's because I don't want to pass my problems and negative moods onto them. Even if you aren't feeling that great, don't put other people down too by giving a negative vibe. I'm not saying don't be sad and don't talk about your problems, but if you can help it, try and be as positive as possible.
If you're feeling happy, show it. Go crazy, because it can really influence other people's moods. If you're in a good mood, share that with others. They'll be in a better mood and can share their positivity around.
As I said before, surrounding yourself with negative people won't help you feel any better, so try and avoid that. Surrounding yourself with positivity will make you feel a lot better and that's good, there needs to be more happiness in this world.