almost homeless, patching old house cheap

I have an old house the shingles have rotted away and the deck has holes in it, It is a steep roof. I got a bunch of white membrane I think it is tpo, or possible pvc. I nailed some aluminum flashing over the holes and I am putting that membrane down with a bunch of nails with plastic washers for synthetic underlayment. What products can I use over the nails and washers? looks don\’t matter!! can I use cheap fibered asphalt? can I use aluminized roofing tar? can i just paint it over and over with latex paint?