We have used density functional theory of freezing and hypernetted chain(HNC) integral equation theory to investigate the effects of gradual softening of inverse-power repulsive interaction on the structure and fluid-triangular-solid freezing transition of a one component system of particles confined to a two-dimensional plane and interacting via core-softened potential. We have also performed Monte Carlo simulation to test the accuracy of the pair-structures obtained by HNC theory and to see the equilibrium configuration of particle in different thermodynamic conditions. The pair-structures are found to compare well with those obtained by MC results, particularly in high softness parameter region. The radial distribution given by HNC exhibits a non-monotonous behavior with the change in particle density in addition to the emergence of a new peak at shorter distance. In contrast to HNC, the RDF, obtained by MC simulation for high-softness parameter, display a splitting of the second peak at high density.