Where can I call to get STD Test?

Look up Planned Parenthood -- you can get help and advice there, and there are PP offices almost everywhere. If you don't like that option, try looking for your city, county or state Board of Health and call them. You'll have to use a phone book for that one. Certainly any physician you see -- I'd recommend a general practitioner -- should be able to answer you and give you reliable and confidential info. But that will probably cost you a fee, unless it's a public health clinic. If you have a school counselor (assuming you go to public school) you should be able to get reliable information there, but ask questions before you reveal anything about yourself.

go to your doctor and ask to do a test on you

Your family or primary care physician would be a good start. If you don't have one, most urgent cares do STD testing. Failing that, there are kits you can buy at your local pharmacy, but I would recommend starting with your doctor. Some states also offer free or low cost testing. You can do a search for free STD testing to find out if there are any near you.