Paper as build surface - how will that work?
Blue masking tape is a common bed surface, especially for unheated beds. It is effectively an adhesive applied to a paper, although I suspect the paper is treated in some manner to serve as a barrier to paint, as the blue tape is sold as paint masking tape.

A sheet of ordinary paper isn't likely to catch fire, as the bed temperature will not reach combustion temperature for paper (more than 230&nbsp;°C), but you still have to have the means of providing adhesion of the paper to the bed.

A thick enough weight of paper may provide sufficient rigidity to provide for a stable print surface, if the perimeter is well secured and uniformly (smoothly) attached.

You'll have to experiment with various types of paper surfaces as well, as some may be treated (calendared) during manufacturing, which could affect the results.

Blue tape is your best bet if you want disposable. Also if you use care in removal, it is not a single use bed covering.