Idk what to do.... I really want to write it in 1st person, but how can I show other characters point of views without having to dedicate a chapter?

You have the other characters express or imply their points of view towards the protagonist. The reader can then infer that there's more than one viewpoint and that your narrator may not be entirely reliable. This is a godo thing if you can pull it off.

Make sure that the characters are in an identifiable context ie surrounding setting

Then don't write it in first person.