When can I check my credit and possibly get a credit card?

I bought my car, with a co-signer, exactly one year ago. This was my first form of credit ever. I'd like to know where my score is, if it is anything. When is a good time for me to check it? I also would like to get a credit card to a small place like a jewelry store or Target (although I know the interest rates are insane). I;m just looking for something from one specific place with a small limit that can help me continue to build credit. When can I start looking into those?