I believe connecting with your school's foreign study office is best to see what programs are sanctioned and most importantly what programs will provide academic credit for your study. There are many for profit programs including Education First which may also be approved and sanctioned. You also want to see if you can get scholarships or aid for any of your programs.
I think it is wonderful that you have decided to pursue study abroad. As the answer above points out, your college might have an office or counselor that would provide advice on study abroad programs. Make sure you choose when where you would get full credit for the classes you take. If you are looking for a specific provider of study abroad programs, try the School of International Training (SIT).
They are based in Vermont but they offer very interesting programs all over the world. I attended their programs in Brazil and Switzerland and had a wonderful time. Good luck!
Education First is a great program to ensure a fun and safe visit. I personally attended API Florence, Italy and found it completely organized. I got free excursions, free safety lessons, new friends, and phone numbers to call in the middle of the night if I was in trouble. 10/10 would go again.
I would say start with your career counseling office, or like many others have said your foreign studies office on campus. They are able to provide you with resources that will not only allow you to travel, but could provide some credits towards your major. My very first international experience was a study abroad program to Costa Rica through my university. I took an intensive Spanish course during the semester, and then spent 3 weeks during the summer in Costa Rica going to classes and living with a host family, all through the university. Going through your school you may be able to get scholarships and additional aid to assist in paying for your program as well!
Best of luck in your journey!!