  Underlying events dominate most of the hadronic activity in p$-$p collisions
and are spanned from perturbative to non-perturbative QCD, having a sensitivity
ranging from the multi-scale to very low-x scale physics. A detailed
understanding of such events plays a crucial role in the accurate understanding
of Standard Model ()SM and Beyond Standard Model physics. The underlying event
activities has been studied within the framework of Pythia 8 Monte Carlo model,
considering the underlying events observables mean charged particle
multiplicity density , $\langle d^{2}N /d\eta d\phi \rangle$ and mean scalar
$p_T$ sum, $\langle d^{2} \sum p_{T} /d\eta d\phi \rangle$ as a function of
leading charged particle in towards, away, and transverse region of p$-$p
collisions at $\sqrt{s}$ = 2.76, 7 and 13 TeV. The towards, away, and
transverse regions have been defined on an azimuthal plane relative to leading
particle in p$-$p collisions. The energy dependence of underlying events and
their activities in the central and forward region has also been studied. The
effect of hadronic re-scattering, color reconnection, and rope hadronization
mechanism implemented in Pythia 8 has been studied in details to gain insight
into the different processes contributing to underlying events in soft sector.
