I have also used taekwondo in self defense. I have said many times over the years that there is no art that is a silver bullet. That includes TKD, any ryu of karate, MMA, or Krav Maga.I just wanted to add my fathers self defense experiance. He learned tkd from the ymca. Has no idea what federation it was, nor does he care. He has used his several times, including one multi attacker mugging in which he came out on top. From what i know of his training, his teacher had his class fighting each other and guys from korea all the time. I dont know if his teacher did much "realistic" training or not. Tho considering what happend and how he handled them id say he did ok. What are your opinions on this? Was it a lucky fluke, or did he luck out and get a fantastic teacher? Sadly that man is nolonger teaching. I still love watching him do his different katas that he does from time to time.
In my thoughts im drawing heavily from his experiances as well.
Of course he may just be a seriously tough person lol, who learned well and applied well.
It is not a question of whether or not your dad's teacher was realistic, but he trained with a mindset that enabled him to use it when time came. Also, I'd bet dollars and doughnuts that his basics were rock solid.
It doesn't matter what the art is. Train the techniques so that you can use them without thought. Train them against resisting opponents so that you know what it is like to give and to receives blows. Most importantly, so that you can learn to not be afraid of the mean machine that may want to kill you.
Frankly, I think you are off to a great start. You are getting yourself into better condition and seeking out a place to train. Don't worry about the what. That will take care of itself. Just find the place that is the best fit for you. I think Tez' advice regarding starting out with a TMA first is very sound, but in the end, it is your decision to make and your path to take.
As you train, study up on self defense. JKS gave you some excellent places to start. Keep the mindset that whatever you are training in, you may have to use it for real. Separate out what is 'arty' from what is meat and potatoes.
Remember, basics win fights, both in the ring and out. A solid foundation will serve you better than anything else. Look at your dad's experience.
Best wishes to you!!
Daniel