  We calculate the elastic form factors and the Generalized Parton
Distributions (GPDs) for four low-lying bound states of a demonstration
fermion-antifermion system, strong coupling positronium ($e \bar{e}$), using
Basis Light-Front Quantization (BLFQ). Using this approach, we also calculate
the impact-parameter dependent GPDs $q(x, {\vec b_\perp})$ to visualize the
fermion density in the transverse plane (${\vec b_\perp}$). We compare selected
results with corresponding quantities in the non-relativistic limit to reveal
relativistic effects. Our results establish the foundation within BLFQ for
investigating the form factors and the GPDs for hadronic systems.
