A credit card would be useful if you are travelling to 'many'
different countries. I'd check the fees, associated costs and
accessibility, if you are going to use one overseas. I think some
of the other posts have also correctly pointed out that you might
want to be mindful of whether you hav the money to travel or just
travel off credit.....because the latter might leave you with a
bill afterwards that might be hard to clear.
Find a travel buddy if you can, but otherwise you'll probably
meet many others on the road. As a lone female traveller, be a
little more wary.
Travelling is the stuff.