The principal goal of the present investigation is to inspect the flow characteristics of an electrically conducting hybrid nanofluid containing copper and graphene nanoparticles past a linearly stretched sheet with velocity slip condition at the interface. Since, the non-Newtonian fluid models result in a better understanding of the flow and heat transfer attributes of the nanofluids, therefore, non-Newtonian Maxwell nanofluid has been chosen as the base fluid in our study with an unsteady magnetic field applied at a certain angle to the direction of the flow. Consideration of thermal radiation along with heat absorption under the mutual influence of viscous and Joule dissipations is one of the key features of this research investigation. With the help of similarity transformations, the governing flow equations have been converted into a system of coupled non-dimensional differential equations. After that, Shooting method along with Runge–Kutta–Fehlberg numerical technique is employed to find the solutions for velocity and temperature of the hybrid nanofluid. The obtained numerical results are well demonstrated with a number of graphs and tables. Apart from this numerical technique, a statistical method is implemented of multiple quadratic regression estimation analysis on the various graphs of skin friction coefficient and wall temperature gradient to establish the connection among physical entities and heat transfer rate. The applications of this investigation in solar energy, ventilation, heating as well as refrigeration , medical science, defence sector etc. Some noteworthy findings include that Maxwell parameter, velocity slip and porosity have a tendency to reduce the hybrid nanofluid velocity whereas graphene Maxwell hybrid nanofluid’s temperature is getting enhanced for rising the values of magnetic field’s inclination angle, radiation, unsteadiness parameters, Biot number and viscous dissipation whereas a reverse trend is visible for heat absorption parameter. Furthermore, the permeability of the porous medium has a more significant impact on changing the nanofluid velocity than that of magnetic parameter whereas the rate of heat transfer is high sensitive for thermal radiation than that of viscous dissipation. As per authors’ knowledge there is no such attempt where the mutual effects of hybrid Maxwell nanofluid (graphene and copper), porous media and viscous dissipation have been considered.