One of the best self defense tools you can have is a Kubaton otherwise known as Striking Tools. These allow you to quickly be able to strike your attacker so you can scream and run away.
Here is a video on how to use one. I do not recommend this for your overall training - you should seek out local self defense training but this will give you some tips.
The Striking tools shown below are the Sock It To Me striking tools that attach to your key chain so they can always be in your hand / easily accessible. These are in different colors and are available from Damsel In Defense. You can get yours from my website www.mydamselpro.net/PRO13361.