Hi everyone!

So I'm new to both E- Budo and martial arts in general. I'm looking for a good dojo to take up judo, karate, or any other recommended martial art. A couple questions:
1. What is a useful martial art to know? I live near a somewhat rough area and I walk to/ from school every day, which is the reason why I (and my parents) have thought of martial arts. I understand that it's not so much the style of martial arts as it is my commitment, but any suggestions?

2. Is there a good dojo that anyone can recommend inside the loop? My parents have really busy jobs and it's best if we can find a place close by...

3. I've heard a lot about "McDojos", and have read up about them... Can you tell me more, especially how a total newbie like me can tell the difference?

Thanks!

S. Tan

(Oh, and if I've broken any rules of the forum, I apologize beforehand- I have no experience in this field, either )