If you can get hold of some audio lessons, you can put them in your audio player to listen to when out. Alternatively if you already know some english, you can put songs or poems etc to start off. Next, you can go to the language exchange section and search for people who want to learn Arabic and know English. then you can mutually follow each other, add yourselves on skype and teach each other :)

Here are some language partners for you to contact http://www.italki.com/partners/1-Arabic-English--200-0--0-0.htm