Cranks but no start and can i reprogram key

What is your question?

My car cranks but no fuel pump or power at the pump. Put in new crank position sensor still same thing. im homeless and live in that car. If key needs to be programmed can i do it myself? Also battery not holing much charge

What makes this problem better or worse?

Same no start

How long has your 2008 Mitsubishi Eclipse had this problem?

1week