Don't use TV shows as a guide for facial expressions/speech patterns! A lot of things that characters do are exaggerated for entertainment, especially in cartoons or action-packed programs. Discreetly observe your peers' lingo, faces, reactions to certain topics of conversation, etc., for a better representation of how you 'should' be acting around them.

When trying to choose how to dress, simple is best! You don't need to wear trendy clothes to seem basic in them, and you don't have to sacrifice your comfort. Any articles of clothing can work together if you want them to, and a simple large t-shirt with leggings can be both cute and sensory-friendly!