We present the two different tunes (A2 and Monash) for Monte Carlo simulation of proton-proton (p-p) collisions at center-of-mass energies of 8 and 13 TeV and its implementation in the PYTHIA8 event generator. We examine the distribution of charged-particle multiplicity as a function of transverse momentum , as well as the average transverse momentum as a function of the number of charged particles in each event. The measurements use charged particles with transverse momentum more than 500 MeV and absolute pseudorapidity less than 2.5 in cases when at least one of them satisfies these criteria. Lastly, a comparison is provided between the experimental data from the LHC experiment for p-p collisions at = 8 TeV and 13 TeV, corresponding to integrated luminosities of and , respectively and the simulated results obtained from the tunes. The results indicate that PYTHIA8 Monash provides the most accurate overall description of the data. It best reproduces the charged particle multiplicity distributions, distributions, and . However, PYTHIA8 A2 shows a better agreement with the multiplicity data more than PYTHIA8 monash, particularly in the low and mid- regions at 13 TeV.