can you get married if you have an outstanding arrest warrent?

Yes, you can.  I don't see any reason why not.  However, if there is an outstanding warrant, you run the risk of being pick up if you don't turn yourself in.  This allows you to control the process and avoid the embarrassment of being arrested in a public place, at a time that you don't expect it.  Further, it is better to turn yourself in and bond out, at your convenience.