You are in the vicinity of the Republican Basilica Sempronia with its Tabernae Veteres (old shops), which became the Basilica Julia when reconstructed first under Caesar, and later Augustus. You can enter from the Vicus Jugarius on the western side of the building, the Vicus Tuscus on the eastern side, or directly from the Forum. You will find out more about the Basilica Julia here and this reconstruction will give you an idea of its shape, while this drawing of the Forum shows the basilica in context.
Reconstruction image courtesy of UCLA's Digital Roman Forum.
Steps of the Basilica Julia