Currently I am unemployed and I haven't done my taxes since 2015. I am starting my new job in January. Should I wait after I have money, to do my taxas? What should I do?

I Jumped jobs because I was looking for full time. I have a job that is full time but I am unemployed currently and on a negative budget. I didn't do 2015 tax refund and so now I do not know what the next step it is I should take. I need guidance on to what I should do next?
Thank-