Travel fees for volunteering projects

I am starting a few volunteer projects this year for vulnerable women and children all over London and England. 
I live and work in London but the cost of commuting is quite expensive and I feel guilty depending on the charities to compensate me.
I don't expect much, but if people can help me get to these places and help those in need or vital support and education then I would truly be very grateful.
I am passionate about caring for those less fortunate and hope this volunteering will help my application for a masters in Women and Child abuse.