Applying for a part-time job is a little different from applying for a full-time professional position. Dress should be, at the least, neat and tidy. Business casual is usually appropriate.
What to wear to a job interview so you can stay cool in warm weather, including business and business casual interview attire for men and women and tips for keeping it cool when it's hot outside.
How to tie a tie, plus tips for dressing professionally for a job interview.
The first impression a prospective employer has of you should not be just a good one, but, a great one. The candidate dressed in a suit, with a coordinated long sleeve shirt or blouse, conservative shoes, a professional hairstyle, and limited jewelry and perfume or aftershave, will make the best impression.
When you're interviewing for a non-professional level position (in a store or restaurant, for example) business casual attire is usually appropriate. It is always important to be neat, tidy, and well-groomed and to present a positive image to the employer.