Faxing for a 56 year old dinausor here ?? what should I use please read:?

The only way I know how to fax is to drive to staples and pay money, is there a software program or ?? online site AS I ONLY NEED IT RARELY BUT ALSO I AM 1/2 SICK AND IT IS DIFFICULT FOR ME TO GET OUT so even if software costs more, in the long run would it be good and I have windows xp bought compaq puter in fall 2006, it has fax icon, can I fax if I only have one phone line, I have dsl, Geez, I know nothing about this , simple help is best thanks remember I am poor and sick thanks but trying to do online business