Total load over a beam? or you need to know support reactions?
total load is calculated by summing up all the loads like point loads, uniformly distributed loads, uniformly varying loads, and dead load (density-25kN/m3 * c/s area * length). wind loads, torsional loads etc,
for calculating end reactions, which ,means, support reactions, you have to look at it stability conditions.for this,
you should know the end conditions,
equilibrium conditions are formed as equations based on these end conditions and assuming that the material of the beam is homogeneous over the entire span, you can calculate the loads.
for the calculation of statically indeterminate structures, you will have to follow Finite element Analysis, like stiffness matrix method or flexibility matrix method.