If you don't want to be a cashier just don't apply for that position? If you're planning on applying in a supermarket, when you fill out the application form, you just tick the positions you want to apply for. Some examples of these include nightfiller, sales assistant, check out, produce, deli, etc.
Like others have stated just download a resume template and be sure to keep it under 3 pages. Templates are fairly straight foward to follow, you should be fine. Also be sure to download a cover letter template. This is the letter you attach to the front of your resume to catch the hiring manager's attention. It states why you are interested in the job, why they should hire you, your experience relevent to the position, etc. Make sure you keep this letter as positive as you can, straight to the point, and 3-4 paragraphs max. A lot of hiring managers will not even look at a resume if there is no cover letter attached.