To choose the best supervisor role, you should take into account your personality, work experience, and interests. More than likely, you will have more luck finding a supervisor position in an industry you are familiar with. You should also choose something you will enjoy doing and find interesting. That way, you don't get bored and can perform better work.
Start by looking into the company you are currently with. If you have been working there long enough to have a firm grasp of what they do and how it should be done, this could lead to a supervisor role if one becomes available. Working your way up the chain of command in this way is one of the best options for breaking into management and beyond. That said, if you do not enjoy the industry you are in or do not get along as well as you'd like with your current employer, it may be time to look elsewhere.
You can find potential positions by reaching out to companies in industries you have experience with. This can include your current job as well as positions you've held in the past. If you have a particular company in mind, go directly to their managers and discuss potential employment opportunities. Even if a supervisor role is not available, you can gain experience and work your way up within the company.
Attending college is another way to gain a supervisor role. To give yourself the best chance of getting the job after graduation, major in something related to either the industry you're interested in or management in general. In this case, you can begin talking to employers in the months before graduation to secure a job in the field you want.
If you have prior experience in a supervisor role and simply want to switch companies or industries, the steps you take would be much like any other job hunter. Check in all local classifieds for job openings and call or send your resume. Talk with friends and families who may be able to refer you to an employer, and network with as many past and current colleagues as possible.
You may also consider attending local job fairs. These are events held by organizations that feature employers in your area who are hiring or will soon be hiring. They allow you to meet with these people, fill out applications, submit resumes and network with other job searchers.