You would be better off staying at home eating a pack of potato chips than doing
some of the self defence techniques that I have seen in the past.
I have personally trained in various martial arts for the last 10+ years of my life and in that time I have studied a wide range of techniques and styles. What I have learned is that most styles out there including the heavy hitting ones like MMA don't work on the street. I found this out the hard way.
I've won many competitions and medals through my fighting career but when it was time to use it in the real world I absolutely failed. The worst part is I got decimated by a guy much smaller than me. I was lead to believe that the techniques that I had learned in the Dojo would protect me in real life, I was so wrong.
These fancy moves that had taken me 10 years to perfect where outdone by a small but brutal street fighter with no technical knowledge. I was disappointed, all that sparring I had done with my fight partners and all that money I had paid out to expensive self defence classes and I still couldn't beat a common thug.
So if you're a beginner and want to look at getting into a self defence class then have a look at it before hand and see for yourself if you think it looks rubbish. If their teaching fancy techniques which appear complicated chances are that you won't be able to perform these defences in real life.
I do recommend you checking out online for a self defence class that specialises in street fighting, if you do this your 85% ahead of the competition already.