If you find that you only want to date Jewish guys, you should think about why this is. Is it because you think Jewish guys have certain physical features you find hot? Is it because of Jewish stereotypes you find appealing? Is it because you’re attracted to Jewish culture and tradition, and want to be part of it?
If it’s either of the former, you could be fetishizing Jewish men. Racial fetishization is taking physical stereotypes or parts of someone’s culture and objectifying people based on them. Jewish men aren’t exotic items to feast your eyes on. But if you are fetishizing Jewish men, just be aware of this and work to change that. Learning more about Judaism and Jewishness could really help you keep from getting bogged down in the stereotypes. Learn how to respect Jewish men for who they are, rather than getting caught up in what being Jewish stereotypically entails and seeing Jewish men as inherently one thing or another.
If it’s the latter, then it might be a good idea to explore Judaism. There are better ways to get involved in Jewish culture than by simply dating a Jew, and if your heart is leading you towards Judaism, follow it. But if this is the case, listening to what people around and the media say about Jews is just not enough. You need to get involved personally and see for yourself. Join a synagogue, talk to a rabbi, talk to Jewish people of different backgrounds, join a Hillel. Make sure what’s attracting you to Judaism isn’t just a hodgepodge of stereotypes.